Diversion is a mobile one-button platformer by Ezone that I enjoy. Myself I play the ad-free version on iOS, Diversion For Kids.
Every five stages we get a mini-boss, but we have to wait all the way until the 30th stage of a world to see the world boss.
But honestly, I don't think most of the Diversion bosses are particularly "epic". It'd probably be hard to work a really memorable boss into a one-button platformer. (But I do think the world 6 boss is pretty awesome! :) )