Cubivore is a one player Nintendo GameCube game produced by Atlus that was released on 8 November 2002. It is rated E (for everyone) for suggestive themes and violence. Most of the big stores don't stock the game because it's too weird for mass appeal, but you can usually find one or two copies in the little vidgame shops at the mall.
In Cubivore, almost everything is made up of rectangular solids -- creatures, plants, goodies, etc. There is just a smidge of terrain that violates this standard. Even "you" are a creature made up of a cube and some number of flaps of "meat."
Your largest goal is -- just like real life -- to get laid...er, mate. You do this by defeating big critters, gathering love bits, and hooking up with females in the periodic Love Tunnels. Apparently chicks dig a Cubivore who can kick ass. When you mate, your old creature dies and you take the form of your progeny -- a new one that is a cross between your old form and one of the females with whom you hooked up. You get to choose the child that replaces you from among the number of chicks you successfully knock up.
Along the way, you collect meat of various colors (each of which has special properties that are conferred on you when you’ve completely turned that color), snackgrass to fill your stomach (heal), love bits (and bugs) with which to turn on the women during mating, training bits (cubes) that eventually confer special powers, and raw meat. Raw Meat is contained only in the boss (tough creature) of each level. You have to defeat him in order to move past that level and into the next. Gaining the boss’ raw meat opens the door out, enables your mating, and confers special abilities (e.g. extra defensive prowess).
The colored meat flaps come in five colors and two shades. Creatures of these colors have different abilities based on the configuration of their meat flaps (limbs). Darker shades are more powerful than light ones. It really does pay off to learn the strengths of the colored forms and use those strengths in battle. The colors work like this:
The game is quirky. It appears to have bad graphics, but it’s clearly by design. Evolution is strange -- allowing you to change forms willy-nilly, but that’s kind of the point. The mechanic that allows the game to just keep going for a long time -- starting you over periodically as a different base animal feels like a poor hack rather than an elegant solution, but other than that I don’t have much in the way of complaints. Super Mario Sunshine is way more polished, and may end up being the best GameCube game of ’02, but Cubivore is certainly the most novel (with Animal Crossing pretty close behind) and is a pretty interesting play. You could certainly do worse with your $50.