Game 2.0 is a semi-regular column dedicated to exposing the gaming community at large to the wonders of user-created content.

All over the world, students and enthusiasts alike produce unique and compelling games from scratch, and whether they do it for the experience, as a learning process, or simply because they love to create games in much the same way that others love to play them, the fruits of their labor are generally made available to the public gratis.

Fans of any genre of gaming from adventure to puzzlers will find no lack of free games in the vast reaches of the internet, but to simplify the process I've compiled a varied list of some of the most entertaining ones I've encountered over the last few months. I also encourage any readers who have a favorite free game to comment about it and spread the word-those developers who put their hearts and souls into creating these gems deserve all the recognition they can get.

Acidbomb 2: Rearmed

Best described as a combination of Picross and Minesweeper, you must solve a series of puzzles-each of which is actually a bomb-by deciphering clues and using intelligent guesswork. Should the time limit run out or your detective work prove faulty, it's not only game over for you, but also the free world. Though this game is free, be on the lookout for the commercial release, titled ShellBlast, which will come with two new game modes.

...And Yet It Moves

One of the top ten submissions selected by the Independent Games Festival to represent the 2007 Student Showcase, ...And Yet It Moves is a side-scrolling platform game with puzzle elements that features a unique, paper-drawn art-style and the ability to rotate the world ninety degrees in either direction. Guide your paper-crafted hero through two levels by using your world-altering power to clear his path.

Blocksum

Blocksum is an addictive action/puzzle game designed for, as the author's website puts it, anyone that can count to twenty. As the screen slowly fills with numbered tiles, you must combine them to add their values and clear them by matching up a number of adjacent tiles equal to the value of those tiles. Though it sounds complicated in writing, it's a remarkably easy game to pick up, and one that I would rank high in the pantheon of similar puzzlers.

Every Extend

The independently developed shoot'em up that inspired Tetsuya Mizuguchi of Lumines fame to create Every Extend Extra and the upcoming Every Extend Extra Extreme , E2 is an unusual game in which your only means of defense is to orchestrate your own destruction. By self-destructing, you create chains of explosions to score big points and extra lives called "extends," all in the name of lasting long enough to defeat the boss characters that appear after a predetermined amount of time.

Frets on Fire

A freeware alternative to the massively successful Guitar Hero franchise, Frets on Fire allows you to import your own music (or the official tracks directly off the Playstation 2 discs) and rock out on your keyboard. For a more authentic experience, the game also supports the PS2 axe controllers via USB adapter or the new Xbox 360 X-plorer guitar. Now you too can be a paranoid android.

Knytt

Full of charming graphics and enticing gameplay, take command of Knytt as he must search the strange and wonderful world he finds himself stranded on for the pieces of a wrecked spaceship so he can find his way back home. Encounter a variety of friends and foes through this incredible adventure game akin to ICO and Shadow of the Colossus-games that the creator, Nifflas, has cited as inspirations-all while taking in the beautiful scenery of what feels like a living world.

The Terrific Menace of the Invaders from Audiogalaxy

When the evil King Mix, deposed despot from Audiogalaxy, plots to conquer the Earth using music and time travel to begin his intergalactic reign of terror anew, it's up to The Hero, a self-proclaimed computer pirate, to save the day. Besides having an awesome name, The Terrific Menace of the Invaders from Audiogalaxy is both amusing and entertaining, and was designed in part as homage to, and as a worthy successor of, the titles from the golden age of adventure gaming.

Toblo

The winner of the 2007 IGF Student Showcase Best Student Game award, Toblo was also the only academically developed game to be nominated in the main competition. Do battle as a member of either the Cloud Kids or the Fire Friends-using pieces of their colorful and entirely destructible world itself as weapons-in this fun and charming capture-the-flag game.

What Linus Bruckman Sees When His Eyes Are Closed

What does Linus Bruckman see when his eyes are closed? Do you ever find out? Do you want to find out? The answers are, not surprisingly, within this strangely compelling retro adventure game in which you play through two separate storylines concurrently: guide a nameless female samurai as she struggles to save the goddess Izanami while you simultaneously lead an intergalactic fast-food heir in his quest to save the family fortune from his useless father's gambling problem. Yeah. Wrap your mind around that.

Within a Deep Forest

Another game developed by Swedish superstar Nifflas, Within a Deep Forest, like Knytt, creates a working representation of a teeny-tiny living world of wonder. Unlike Knytt, this is an insanely difficult platformer that features an in-depth yet entirely ridiculous story: a sentient bouncing ball must stop his creator, the evil Dr. Cliché, from detonating a bomb that would freeze the entire planet. In a bizarre combination of Metroid and Mega Man, absorb new powers to alter your ball so you can continue to explore the vast world and quite literally meet your maker.