Here's my second prototype, written as part of the previously-blogged-about RocketHands end-of-year idea creation phase, or REOYICP.
The concept is simple: a two-player co-operative single-screen platformer, in the vein of Bubble Bobble, which is challenging for hardcore gamers but friendly and inviting to non-gamers. The motivation is to allow mismatched partners to play together, be it couples, siblings, parents and children or whatever.
Players share everything - score, loot, powerups and so on - but only one player can lose a life. That player is impotent, and can only convert monsters to fruit (by stomping on them) with the help of their invincible partner, who can shoot monsters to render them vulnerable to a stomping.
The skilled player (the impotent, stomping one) can control both characters, either to play a single-player version of the game, or to get their non-gamer partner out of a tricky situation. This means that the invincible player can jump in and out of the action, taking part in a meaningful way without feeling overwhelmed or threatened, and without worrying about ruining the game for their partner.
Just an idea, is all. Written in 12 hours in RubyGame. Much of the time was spent writing an importer for levels made in the most awesome Ogmo Editor, which you should all download immediately.