Astal - Was more difficult than I was expecting. Very interesting game though that I'll go back to at some point to try and finish.
Bioforge - Bit awkward to control, but seemed interesting.
ChuChu Rocket - Not my first choice of multiplayer game, even on the DC - I'd go for Power Stone 2 first. It's OK though.
Eternal Darkness - Personally I think everyone should have a Gamecube just to play this.
Mischief Makers - I normally stay well clear of anything with an anime style to it, but I like this game.
Zillion is cool, but found it pretty confusing trying to figure out where I was going/where I'd already been.
I don't really see what the big deal about Hellfire is. There are loads of other Mega Drive shoot 'em ups that I'd rather play. Zero Wing, Gley Lancer, Arrow Flash, Thunderforce IV.....
The Neverhood is a game that I always wanted to play.