Pros:
- Fun game loop / mechanics
- Standard but good powerups elements.
- Liked the effect on the E "interact" when approaching the void
- The coin sound were enjoyable & encouraged the player to keep on going
- Nice that you had time to add menus & key rebinding.
Cons:
- Sometimes monsters took way too much time before appearing.
- Sometimes monsters simply appear on top of you.
- Issues with inconsistant movement speed depending on diagonal vs linear directions.
- Starting a new game, if you stay at the safe point for a while, the game seems to think you played a long time & you get killed instantly because you can't compete yet with 5 head skulls.
Comments:
- Probably normal, but coins seem to disappear after a few seconds. I think blinking them a few seconds before disappearing would be a visual help for players to hurry and get them.
- Add some music. I played with some drum and bass & made the experience much better.
- Game difficulty caps quite quickly after you get a few upgrades. At the end, even if I wanted to make myself die, it was impossible with the health regen XD
As a web dev myself, I'm very impressed by the fact that you created your own engines features.
Good job!