Vectorman (Genesis, 1995)

After Donkey Kong Country was released for the SNES, Sega must have been feeling some degree of embarrassment.  They had for so long claimed that their Genesis was the graphically superior of the two, but still needed to release add-ons like the Sega CD and 32X to give it a little technical boost.  Donkey Kong Country was a game that looked just as good, if not better, than games for either of them, and it required nothing more than what the SNES already had.  So Vectorman (1995) was released as something of a response to that.
Vectorman is possibly the best looking game for the Genesis, as well as one of the latest (by this point, the Playstation was already out and Sega's own Saturn was not far behind).  It uses computer rendered sprites and animations, but still using less frames than in DKC.  The Genesis simply did not have the memory capacity necessary to make a game that good looking.  One trick that is used to mask this is by making characters out of multiple sprites to create fluid animations (a trick also used in great games like Gunstar Heroes and Sonic the Hedgehog 3).  The main character is essentially a robot made of orbs.
The story goes that it is centuries in the future, and mankind has been forced to evacuate Earth due to over-population and pollution (games in the 90's seemed to be fond of faux-environmental themes).  They leave robots behind to clean up in hopes of returning to a cleaner planet.  One day, the robot in charge accidentally has a nuclear weapon attached to his head (go with it) and he becomes Warhead, tyrant of the machines.  He gains control over all of the other robots (except for Vectorman, a sludge barge driver) and plans to destroy the humans upon their return.  Only you can defeat him and restore peace.  Quite elaborate for a run-and-gun game.
Okay, so the plot may be a bit more than necessary and completely ridiculous, but the gameplay makes it forgivable.  As stated, your objective in each level is to platform and shoot your way to the end.  It is completely linear, but the stages are huge and sprawling, and there is substantial reward for exploration.  There are also special stages in between the main levels which add some variety.  The control is simple, yet responsive.  You jump with one button and shoot with the other, and Vectorman can perform a double jump.  This is another game where the double jump makes logical sense, since the eponymous robot has boosters on his feet.  You also get temporary power-ups, some that give weapon upgrades, or transform Vectorman to give him special abilities needed to progress at some points.
It is the subtle touches that make this game great.  The attention to detail in this game is extraordinary for a Genesis title.  When you shoot straight down in the arc of a jump, it will slow Vectorman's descent.  Combine that with the double jump and you can make very precise jumps and maneuvers.  If you double jump right over an enemy, they will take damage from the propulsion exhaust.  Some minor graphical details are impressive, such as the lighting effects.  Vectorman's sprite will change shade in accordance with the lighting.  Another amusing touch is in his idle animations.  When you stand still, he will amuse himself by juggling some of the orbs that make up his body.  Stand against a wall, and he will lean against it in a cool pose.
On a system that is famous for high-quality platforming and action games, Vectorman stands out as one of the best.  It would receive one sequel, also for the Genesis, which was vastly overshadowed by both its predecessor and the next generation of gaming.  The first game was barely early enough to have been successful.  Once the Playstation had been released, it was time for both Sega and Nintendo to move on from their 16 bit systems and look forward to an age of polygonal graphics and 3D.  Vectorman can be seen as a fond farewell to the Genesis.

Sonic the Hedgehog 2 (Genesis, 1992)

A great video game sequel ought to expand and perfect the gameplay of the first game.  It should not just be a retread of the same formula, but stay true to what made the original special.  It should iron out the flaws of the original game while avoiding making new flaws.  It isn't very hard for a video game sequel to be better than the original, but there are instances where a sequel takes a major misstep.  On the other hand, you have fabulous games like Sonic the Hedgehog 2 (1992) which are everything I described as a good sequel.
The game basically continues the plot from where the first game left off, with Dr. Robotnic once again trying to take over the world, this time by constructing a doomsday device known as the Death Egg (no, you don't use the force to take it down).  Sonic has a bigger challenge this time, but he is aided by his new sidekick, Miles "Tails" Prower, a two-tailed fox who can spin his tails like a helicopter rotor to fly for a short period of time.  Of course, his name is a not-so-clever pun on the phrase "miles per hour," but I suppose that is forgivable.
Now Sonic has been given one new move for this game, and it feels like a godsend all by itself.  By holding down and tapping the jump button, he can charge up a dash and launch himself from a standstill to running in no time flat.  I can't tell you how annoying it was in the first game to have to run back and build some momentum if you had to get over a slope.  This problem is gone in Sonic 2, and is one of the biggest reasons why it is a much better game.
The other new feature of Sonic 2 is a multiplayer mode, where two players engage in a split-screen race to the finish line in one of four levels from the game.  I usually don't talk about the multiplayer in games because I feel that most games nowadays push their multiplayer in the spotlight while the single player campaign is left to suffer.  Sonic 2's multiplayer doesn't feel that way since the main game is so solid.  It feels like icing on the cake, an additional feature that does not detract from the overall experience.
Sonic 2 also features bigger levels, more of them, and better graphics.  The levels in the first game sported branching paths, but nothing like in the sequel.  There are some areas of the later levels that you may never see if you don't do a little exploring.  They are also more varied and numerous.  The first game had six zones that were broken up into acts.  Sonic 2 has at least twice that.  One level is a marsh with underwater paths and sections high in the trees.  Another level is a giant casino with pinball segments and slot machines, the dark of night illuminated by neon lights.  The game isn't drawn with much more definition than the first game, but Sonic 2 has a brilliant color palette.  Everything is bright and eye-pleasing.
Speed has always been one of the defining features of any Sonic game, but this was the first game to truly use it to its full potential.  The levels are all designed like huge roller coasters.  In fact, this is one of the games used in Sega's famous "blast processing" commercial, where they claimed that Genesis games were faster than SNES games.  This is true, since the Genesis' processing speed is about twice as fast as the SNES' (although in every other techical category, the SNES is superior), and if any game were to be the proof of it, that game would be Sonic the Hedgehog 2.
Like the first game, Sonic can only get the true ending if he collects all of the chaos emeralds, but the way you get them this time is different.  Instead of collecting fifty rings and then going through a big ring at the end of the level, now you need to collect that many rings and go through any one of the many checkpoints in the stage.  This will open up a portal to the bonus round, where Sonic and Tails run headlong down a tubular track, collecting rings and avoiding obstacles.  Collect enough rings, and you are rewarded with a chaos emerald.  Fail, and you are sent back empty-handed, left only to try again next time.
Sonic has become something of a whipping boy nowadays.  His contemporary titles have ranged from lackluster to abysmal.  Who remembers a time when Sonic games were always looked forward to?  His days in the Genesis were a time of constant uphill improvement, rather than a joke.  The Sonic games were always Sega fans' biggest and best argument as to why their system could be superior to Nintendo's.  We are long down the road from those times, but many people still argue as to which system was better.  What's my take on the situation?  Well, Mario has never appeared on a Sega console.

Phantasy Star IV (Genesis, 1995)

The RPG was a genre that was not favored highly on the Genesis.  Sega's 16-bit console was suited mostly to action games that were quick and cheap to produce, not lengthy, expensive RPGs, which were still a niche genre in the States.  The first Phantasy Star game was released for Sega's ill-fated Master System, their equivalent to the NES.  Considered to be a good game, but not very well remembered and a commercial failure.  Phantasy Star II was one of the earliest games for the Genesis, and is well-remembered by fans, but has not aged well.  Phantasy Star III is easily the worst in the series.  However, Phantasy Star IV (1995) is an underrated masterpiece of retro RPGs.
You play as Chad, a new recruit of the Rangers, essentially an emergency response, and police force of the planet he lives on.  He and his friend Alys are sent to small village to investigate a monster infestation.  One outbreak of monsters leads to another one, and before long the cause of them all is revealed to be the doing of a man named Zio.  Zio has been spreading a false religion across the planet, perverting the people which gives fuel to his master plan, resurrect the evil deity, Dark Force.  1000 years prior to this game (in fact, the events of the first Phantasy Star) a warrior names Alis defeated Dark Force and sealed him away.
Phantasy Star IV follows the basic RPG template set by Dragon Warrior, but perfects it.  You may have up to five characters in your party, who come and go as the story goes along.  You gain experience from random enemy battles, and characters level up, gaining new skills at certain levels.  All characters can fight with a weapon, but some characters have different abilities.  Some characters are avid magic users, having the best spells, while some have more techniques, special moves that are unique to each individual character. In earlier Phantasy Star games, the battle systems were rather awkward.  Both II and III used a system where character actions had default sets, and you let turns play on until you won, lost, or told the game to stop.  In IV, This is abandoned in favor of a simple to use menu system, and only one turn plays at a time.
The art style of this game is eclectic, to say the least, but nothing feels out of place.  The game takes place in the distant future, but most technology has been forgotten.  People live in adobe-style houses in desert towns.  Relics of the high technology of the distant past are sealed away deep underground.  You uncover some of these in your fight against Zio, and the include a tank, a burrowing vehicle, a a few spaceships.  There are several planets to travel between, all unique in their landscapes and denizens.  Story elements are told in comic book style cutscenes.  All of this is tied together by an anime aesthetic.
For a Genesis game at this time, it is a fairly ambitious and gutsy game.  Religious materials were still taboo with Nintendo, so in this game, having the themes of false gods, messiahs, and dogma handled maturely and seriously is actually quite remarkable.  Zio promises the people an easy and false route to paradise, at the cost of their souls.  Going into one of the Zio temples throughout the game you will be assaulted with the mindless remarks of the zealots therein.  There is no way to awaken these drones to the truth, you just have to accept that the people you must save are the ones who are against you.
Phantasy Star was always meant to be Sega's answer to Final Fantasy, but do they stack up next to Square's giants?  In short, not really.  These games have always been behind the inventions and innovations of Final Fantasy, but the fourth installment of Phantasy Star does hold up on its own.  By this time, Final Fantasy VI had come out and it was too late for this series to play catch-up, but in its own way is something special that could only be one of those rare RPGs for the Sega Genesis.

Gunstar Heroes (Genesis, 1994)

Treasure were one of the premiere game developers for the Sega Genesis.  Their games are characterized by having some of the most impressive and stylish visuals on the Genesis, which give even the technologically superior Super Nintendo a run for its money.  Their first Genesis title was the quirky and fun platformer Dynamite Headdy.  They also made the Japan-only run-and-gun game Alien Soldier, which features some of the Genesis's most impressive visuals.  Fans generally agree though, that their best game was 1994's Gunstar Heroes, a platforming shoot-em-up, and one of the best games on the Genesis.
In this game, you play as Red (and a friend may play as Blue in simultaneous multiplayer), who must recover stolen jewels that were taken from them by the traitor Green.  An evil General wishes to use the jewels as a means to awaken and control a doomsday device.  A la Mega Man, you may choose which levels you want to play in any order (up to a point).  No two of these levels are the same.  In a genre that mainly only focuses on combat in progressively more difficult environments, Gunstar Heroes uses this combat in completely creative ways.
The first thing that is creative in this game is the combat itself, and the weapon system.  There are four weapon types, and you may combine any two of them to make more powerful weapons.  For instance, combine flamethrower and machine gun and you get exploding bullets.  Combine laser and homing weapon and you get a homing laser.  I usually combine two homing weapons, which creates a kamikaze of rapid-fire homing projectiles.  Add in a broad range of melee attacks and you have a fairly diverse arsenal.
Each level is also crafted to be wholly original.  One level has you rocketing down a mine shaft on a robotic mining cart.  Another level has you piloting a ship through space, shooting at obstacles and dodging lasers.  My favorite level has you playing a board game where you throw a dice, move spaces, and then must complete an obstacle course or defeat a boss.  Another great thing about this game is its creative and challenging boss fights.  There is a large emphasis in this game on fighting bosses, and they are no exception to this game's streak of originality.
No, there aren't any messages or themes to explore in this game.  Yes, it is a game that highly relies on combat as a means for progression rather than creative problem solving.  However, there is an immense joy to be found in this game.  I think that games on the Sega Genesis were most at home in the realm of simple, arcade-style action.  Some of the best games on the system are this way.  Vectorman, Sonic the Hedgehog 3, and certainly Gunstar Heroes, are games that sought to push their platform's technical limitations to the very limits, and deliver a product that impresses and entertains, still to this day.

Sonic the Hedgehog (Genesis, 1991)

Sega is a company that built their whole reputation by being braggarts.  When they released their second home console, the Genesis, in 1989, they immediately began a marketing campaign attacking Nintendo.  "Genesis does what Nintendon't!" the ads proudly proclaimed.  The argument, for Sega fans, was that the Genesis had better graphics and sound (a 16 bit processor) than the Nintendo Entertainment System.  The argument, for Nintendo fans, was "So what?  Nintendo has better games."  This was certainly true.  Nintendo had Super Mario, The Legend of Zelda, Metroid, and a plethora of other great titles, with mascots to give the company a friendly face, not unlike how Disney uses its mascots.  What did Sega have?  Michael Jackson's Moonwalker?
So Sega decided it needed to create a mascot and put him in a great game.  They held a contest at their headquarters in Japan to design him.  Many submissions were entered and considered, but the one they eventually decided on was a cartoon of a black hedgehog, originally named Mr. Needlemouse.  Adding a few tweaks to the design, like making him blue to match the Sega logo and renaming him Sonic, they had their character.
Now they had to make the game.  The first Sonic the Hedgehog game is noteworthy just for how much thought went into its design.  They wanted Sonic to run to show off how fast the Genesis's processor was (which they later called blast processing), but that level of speed would leave you blind-sighted when an enemy appeared on screen.  To eliminate this problem, they gave Sonic the ability to roll into a ball to defeat foes.  Sonic controls perfectly, and he would only improve in each sequel.  Levels have multiple paths and many sections that cater to the speed mechanics.  Speaking of which, it is strange that a game mostly remembered for speed features two levels that require much patience.  There are five levels, each broken up into three acts, and levels two and four stick out as the slow ones.  Level two has Sonic crossing lakes of lava, often having to ride on slow moving platforms and carefully hopping across stones.  Level four is mostly underwater, which slows Sonic down considerably (and drowning is an inevitability).
The story is simple:  Sonic must stop the evil Dr. Robotnik, who is planning to use the 6 chaos emeralds to take over the world, and captures animals to make into his robot cronies.  This was still a time when story took a backseat to gameplay, and Sonic the Hedgehog is all the better for it.  Playing it now, it still feels as fresh and fun as it did back in 1991.  Twenty years on, and the blue blur's early outings are still regarded well, more highly in fact than his recent titles.  Sega finally had something that was worth bragging about.