Cave Story (PC, 2004)

If Cave Story (2004) were just a good game, that would be enough, but it goes far beyond that.  Beginning development in 1999 by a single man (who goes by the moniker Pixel), it would be consistently perfected for five years before its release in 2004 as a downloadable title online.  Considered to be the spark that would ignite the indie games movement, this game is an excellent conglomeration of the greatest games for the NES, with its own personal touches and a great story.
In the game, you are a fighting robot from the surface who has fallen to the caves below in some battle.  You make your way through the first cave to find Mimiga Village, a micro-society of rabbit-people.  They are in a bit of a civil dispute over the arrival of a mysterious Mimiga girl named Sue.  She is seen as an outsider, only befriended by the young Toroko.  While looking for Sue, you witness Toroko being kidnapped by a sorceress named Misery and her giant henchman Balrog, who are both working for a person known only as the Doctor.
This mysterious figure has been kidnapping Mimiga and forcing them to eat the dreaded red flowers, which cause them to become rabid, violent, and mindless.  He'll use them to wage war against the robots of the surface, in a plot for total conquest.  What makes this villain more interesting that most "take-over-the-world" villains is his complete ruthlessness, and perverse pleasure in corrupting the Mimiga.  You and all else who are able to help you must fight together (and sometimes die together) to stop him.
The game is a 2D platforming shooter in the best spirit of the classics.  The most obvious inspiration for this game is Metroid.  You jump and shoot through a large subterranean world, and collect new power-ups and upgrades as you progress.  When you kill enemies, they may drop pieces of gold which can be used to level up each weapon you have, making them stronger and more useful.  For instance, the machine gun weapon at level three can be used as a makeshift jetpack by shooting straight down.  Each weapon has a specific use that makes them ideal in different situations, like in Mega Man.  The machine gun is great for crowd control.  The fireball works well against ground-based enemies.  The rocket launcher packs a stronger punch than the other weapons.
What is great about this game is the heart and weight behind its story.  There are some genuinely dark, sad, and heavy moments in the game.  One that sticks out to me is when the doctor ravages a dragon hatchery, and the prematurely-born flying dragons madly try to defend themselves, dripping with blood.  Animal cruelty is a huge theme at work here.  Friends you make along the way die, often because of decisions you make.  Every choice you make contributes to the ending of the game.
This game is a miracle of the indie movement.  It was one of the earliest, but came out in a time when there was virtually no way to get publicity for low-budget independent games.  YouTube was still a year off, Steam was brand-new, and most of the social media we use nowadays were still not online yet.  In recent years, it has been made available for WiiWare, Steam, and there is even a 3D remake on the Nintendo 3DS, but this is still a game that is remarkably unheard of.  With all the major releases each year hogging the spotlight and making gaming look bad, it is great to play Cave Story and be reminded of why I play video games.