Cheating in SP games is grey depending on the title and how you go about it but generally we're given the tools to do so by cheat codes, console commands or mods in some shape or form.
I don't think the devs had in mind for their game to be cheated given it's all about challenge but it is a SP game(With the possibility for Co-op further down the line from what I recall - which would be an amazing feature). In general using hacks is a grey area in SP games. I wouldn't use cheat engine or anything other than dev console commands in the off chance you trigger a ban on your account(Note, I know this game isn't VAC enabled and there's no anti-cheat in the game it's a SP game afterall but having Cheat Engine installed anyway and having it run in the background no matter what while playing anything with anti-cheat enabled is sure to trigger a ban).
