Not my sort of game ... but that didn't stop me from playing to the end. It's amazing what a good story will do to bring in different sorts of players, isn't it?
The gameplay was very well balanced, particularly the pickups and health. I only died three times, and that was in the last four minutes. It felt quite fair. The flipping mechanic was quite fun, and made for some different considerations than usually need to be made when observing enemy strategies.
The action was crisp and clear. I always knew where the enemies were, and if my shots were connecting, and if I was getting hit. The action felt a little overwhelming at first, but then scaled up very gradually from there, so it worked quite well.
I did get a bunch of errors when the timer appeared at the top, so the timer was just stuck at 4:00, but the bomb still went off and everything, so no huge deal.