It's a well-crafted simulation game, and the rewind mechanic is great. However, there isn't much to do since there isn't a clear goal. Being a sandbox game, it could benefit from having more objects to play with. It seems like there's no limit to how many objects you can create, so I just spammed balls and boxes. The game got laggy, but I couldn't make it crash. However, I'm sure with enough effort, it could be made to crash (maybe not).