Intro was a bit too long and my reset page froze up after a few times. Pretty fast paced, cool concept!

I like the idea.  Being able to reverse time to get out of a bad situation is a pretty neat concept.  I just wish I got to play the game long enough to fully explore that concept.  Mainly, and maybe I'm missing something, but I wish there was a reset button when you lose.  The game just freezes and I have to refresh the page to start over, but before I get in, I have to watch the long intro cutscene every time, and because of the randomness of the enemy placements, sometimes one can spawn right on top of you the moment you start the game. 

I like the intro cutscene as a way to set the stakes and to establish your place in this world, but only the first time.  Like I said, if there was a reset button when you lose that just started the game over immediately,  it would feel so much better and would get the player back into the action immediately.

Also in terms of enemy placement, having an area right as soon as you spawn in that tells the enemies not to spawn near the player would help give the player time to figure out what's going on before getting into the action or potentially losing immediately.

Otherwise, genuinely, I like the idea.  I feel like there's so much more you can do with setting up an arena, maybe having safe zones or walls that close off at a certain time so you need to reverse time to enter, or just in general reversing time to get you out of a hairy situation is a really neat concept.