Don't remember where but something about enimies respawning too much when having to back track. They trap you when you are doing things in reverse. Either that or a lot of platforming is so PIN POINT accurate that I could get  to some area's once, then never get back to them a second time. More than likely a lot has changed since I commented this. I just know I closed the game, was not happy with how destroyed I got by Controls / Platforming / Enemy placement.