That's weird!

1. Do you run the game via Wine/Proton on a Unix-like operation system? (SDL2 may not work properly on those)
2. If you have Windows, is the version of Windows less than 10? (SDL2 may not work properly on older versions of Windows)
3. Is your CPU of x86-64 architecture or you are running it in an emulator? (emulation may break the movement calculation)
4. Have you ever had a similar problem with other games, or is it just mine? (it may be a problem with your input device or drivers)

If none of these is the case then I'm confused on how this bug is possible.

Unless when you say "press" you mean you press the button for 1 frame and you don't hold it -- then yes the character will move on a very little distance. The game does look grid-based and some players might logically assume that the movement system is also grid-based but it's not.

Thanks for your feedback. To be honest the current version is a walk simulator in an infinite procedurally generated world (when I say infinite I mean really infinite, not like in Minecraft). I had to cut corners due to the time limit to the point where it's no longer a roguelike.  You can consider this game a prototype, a fundament to make the actual game after the jam.