Not bad, but...
short and anticlimactic. The ending is very disappointing. Not even a change in music, no exlpoding head, dissolving acid or something that feels like "yay me! I finished the game!"
the puzzles are also all not too complicated, and it is really too short - none of the levels had me go "how the hell am I supposed to do that??" at any time.
Somehow I also wonder: What tragic fate indeed. Imagine - being reborn over and over again, jumping into spikes to build bridges. Now - I don't think he get's reborn at the entrance of the level every time. He probably gets reborn at his "batcave", walks to the building, dies again and again just to climb the levels he had previously finished, just to throw himself against some spikes AGAIN, repeating the whole ordeal. Just to "die" in the last level he probably has to die well over a thousand times overall just to reach the level again as this should increase exponentially.
Also... Doesn't invincible mean he can't be harmed, not that he can be harmed but get's reborn? Immortal might have been more fitting, but, that is nitpicking of course.