I've just bought BubbleHeroes for my Amiga, and am running it via RTG on a CV64.
Seems that the game is all squashed up to the top half of a 320x240x8 screen.
I remember having to overcome this problem myself when writing a game on the CV64 and using an 8bit 320x240 screen. Something about the having to use a double width bitmap, whatever, been a long time.
Anyway, point is, did Arcadia ever release an update for BH?