well as you said, maybe more enemy health and even more damage i think that would be a challenge, but there is always more ways to make the game more challenging, i personally feel like you progress quickly through the game and part of it could also be from the amount of items you can find but other than that there isn't much that could be changed because the game is amazing with the stuff that's in it already and i will say have died multiple times so its not like that good at it but in general i would say maybe it could be a little harder if they did make a cheat like that or maybe even the game itself.