You should make the timer start ticking when the player starts moving, not when the level loads in, so the player has time to plan their routing. Also, screenshake in platformers is tricky and you don't want to shake the camera violently at crucial parts like in mid-air, because it throws the player's balance off. Try shaking the screen when landing instead or making it less intense.
Other than that, loved it! The last level is definitely my favorite.