I really liked the how well suported the main mechanic is: the overlay, the slider on the bottom. The level design is also pretty good in idea, in particular the part with the TNT is super creative. That being said I found the game a bit too frustrating, and the time portal is very unforgiving (throwing you out when riding and object that is rising or if the platform you're standing on disappears for even the smallest amount of time. Also, if you have time, my game's mechanic is pretty much identical to yours.