I really enjoyed how you implemented the theme, it's not exactly endless but it's still a cycle and that's more than what I can say for other games. It should be more than a simple restart button on your game and you've gone a bit beyond and actually required the player to start from the beginning after each life time to make progress in certain areas.
One slight thing that irked me a bit was the level design in some places didn't allow backtracking to a doorway because I missed a jump. There were a couple of times where I would have to sit and wait from 50-90 years old because there's nothing I can do in the area I was stuck in.