(Testing games now out of curiosity; better late than never. ;))

I have just played my way through the game; here are some observations.

• I like the main mechanic of setting the spikes to the higher platform you reached, it is witty. I was surprised how level 2 already got somewhat hard! Anyway, I managed to get to the end of the game.
• I am unsure how the game relates to the constraint (‘Life Is A Tool’).
• The controls are based on a QWERTY layout, while I have an AZERTY keyboard, so I had to move left with the equivalent of Q instead of A! I do not know the details of SFML’s API, but I guess you have a way of getting the physical positions of keys (I know you can in SDL2 and Love2D, for example). Also: this may sound silly, but I was then afraid that ‘LMB’ meant some other buttons that would map weirdly to my keyboard, although this really was ‘left mouse button’. XD Maybe write it fully?
• There is some die-and-retry, because you cannot assess in your first try where the lower platforms are without going (in levels 2 and 3, for example). Not necessarily a drawback in itself, although I tend to oppose die-and-retry; I suppose it depends on people.
• I felt the gun mechanic might be somewhat underused; you can beat some level without shooting some spots, that do not seem to be either helpers nor traps.

My takeway is that the main mechanic has potential. You could make an interesting puzzle-platformer by combining it with some other ideas (the gun may be a trail).