The simple explanation at the start, as well as the single lone sound effect being an explosion got a good laugh out of me. I think this could definitely be expanded on like some others have suggested, but for what it is I liked it.

I was almost unable to get any cat to explode...

A simple but interesting game

I thought the delay between clicking on a cat and it ...erm... exploding was interesting. It did feel more like I was casting an enchantment, rather than firing a cannon. I wonder if there's more you could do with it. Maybe exploding cats could take out others around them, so you time your spells to go off as they bunch up?