I've played DX-Ball 2 for years, but I just started playing Rival Ball. I can't figure out how Fire Ball differs from Ice Ball.

AFAIK, only cosmetic differences exist between Fire ball and Ice ball. Just another power-up to collect (or avoid, if one is going for a score attack).

In short, they both cause explosive damage and they both make the ball big (while the power-up is in effect).

Yeah, that seems right, from what I have observed.
Thanks for the reply.

So I went to the Pottery with Cutter, and of course it was a complete disaster. After smashing our way through 21 sets of pots, Cutter felt quite cocky, being in the lead, and boasted with some clever technique to suspend the ball. He did react, though, when I finally launched off my own ball, in fear that I would aim for a goal. ;)


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Sumer

When I first playing this game, I thought Ice Ball would cause the bricks to freeze and become indestructible, but when I discovered it for the first time, it's just Fireball with different colour.