The concept is interesting. The horde survival was a nice balance of being quite difficult, but still possible. I didn't realize that there was a time limit at first, and it seemed pretty tight for some of the tasks (9 coins, meal number 3). I think I died to the timer more than I died to my past selves.
I think it might have been good to give more time and more lives, as it sucks to die to a timer that you didn't know existed, and then running out of lives means starting over completely.