Played it with a friend, he gave up 6 hours in because it wasn't fun but I finished for the achievement hunting.

If you've played the first 5 minutes, you've played the whole game. It only gets grindier from there. Death means nothing, you just have an annoying load time before you're back in the map with the enemies at the same health they were when you died. So in that essence, it's a very beatable game. You can throw as many corpses you want at the enemy to win the game. The real damage is in how much time this game takes. The puzzles to advance at some spots are level wide; as in, you have to carry a heavy ball from one end of a maze to another, and heaven help you if the puzzle requires you to carry something back. 15 hours to beat the game felt like 40 because of this.

The most useful power in the game was the speedup power, because it helped me leave the game quicker.