Despite experiencing major performance issues once I got into combat, I really enjoyed this and played it to the end. The art is fantastic, from the sprites to the lighting, to the blood splatter. The 2-button controls are also really satisfying, and don't feel like they're shoehorned in just to fit the theme. Great work!

NIce game, unfortunately it gets gradually slower and slower - I had a look at the code, and it seems you've implemented a fixed framerate, but what you forgot is that if the game cannot catch up, its going to do more and more updates per second and never catch up.

You need to put a limit on the number of times it loops to guarantee 1/60 time slices - 4 is a good number, since games become unplayable when they are less than 15fps anyway, and it would mean that if the game is running at 30hz instead of 60, it won't slow down over time.
I couldnt get the game to build (npm build? still no compiled file)

anyway, this should do the trick - it guarantees that the framerate doesnt drop below 15, and it stops the endless accumilation of time owed

var limit = 4;
while (this.accum >= dt && limit > 0) {
--limit;
++this.ticks;
Vec2.Pool.reset();
this.game.update(dt);
Clock.accumTime += dt;
Input.update();
this.accum -= dt;
++Clock.ticks;
}
// we couldnt catch up - fugedaboudit
if (limit == 0) {
this.accum = 0;
}

Thanks for your game!
I played your game along with several others from this jam and 'reviewed' them here: https://n8r8.wordpress.com/2015/12/22/n8-r8s-8-ludum-dare-34-part-1/

Nice graphics and concept. Couldn't figure out how to get through the first door, on Macbook Air. We found out how to move, aim, fire bullets but couldn't get through that door.

Surprisingly fun, making images of colored keys would perhaps have cleared up the confusion (probably with very little extra work).