I wonder if you've played an old flash game called "The Company of Myself"? Your game reminded me of that (but you do something different). Lots of good puzzles and platforming challenges, although I found the level design and checkpoints a bit harsh.
Viewing post in Getting Over It Together with... Myself! jam comments
Thank you very much! Never played that game before and I just had a look at it. There are definitely some similarities, but I think that game is more like recording your action and then playing it back together with your current self, whereas in my game, you have to take care of both yourself and your past simultaneously, which I think are different game experience. As for the save points, I definitely should've added more savepoints which I forgot during the jam. Sorry for the frustration from that.