This game is hard, there are many sections that require too much precisions. Having the hitbox collider size being exactly the same as the sprite boundary may risk unwanted detections(A spike detects the player On the platform while the spike is at the side of the platform). The undo feature would be nice, but I can understand if that won't be taken, because of the decision of having the timer in the game. And one more important thing that is to make the game window scalable or have multiple resolutions. Not everyone has 1920x1080 resolution and playing on browser fullscreen mode may not fix that.
Anyway, the use of assets are well appropriate. The game is well playable. I could finish the game after 30 minutes.