As if you didn't already have enough game coding to do with the Minigame compo, I saw on c64.sk mention of the 1^st Annual 2k Classic Text Adventure competition. The idea is to write a text adventure in under 2k of RAM. Sounds like a challenge. I've only looked quickly at the page, but the rules do appear to be a little lenient - perhaps you could use the ROM and write an adventure game with characters called GOSUB and RETURN? Hmm.