I recommend you not use that asset pack again. Those graphics are blatant rip-offs of the legend of zelda games, to the point where they could be considered copyright infringement. Other than that, you really shouldn't make the player go through a fall that requires taking damage unless there's a plot reason of some sort. I'm not even sure why a game with instant death spikes would have fall damage.
Viewing post in Timothy and the Tower of Mu (Demo - IGMC 2018) jam comments
Thank you for your feedback! Actually we searched a lot about that asset pack and we found it's totally legit BUT, as this is a prototype, we are more than ready to change tiles and everything to our needs after the contest is finished before delivering the final game. Also, we reworked a lot of things: the boss sprite is 100% made by us, same as some tiles, deco elements, animated stars/water and so on, same with musics (except for a free-to-use one). About the gameplay: the game is intentionally made to be "hardcore" and punitive. Of course we can fix and balance everything later, but we choose to apply fall damage to make this game hard and for skilled players.