So steam it's then, I would love to have drm-free version here (but I guess steam is drm-free too?) but on steam it will probably be cheaper anyway (regional pricing). Thx. :)
The game is DRM-free on all platforms. The only thing you could potentially miss out on by getting the game on Steam instead of itch.io is the version for Android devices.
Regardless, if you want to support the game and the developer the most, then buy the game on Steam and write a positive review. It helps us reach more customers on the most popular platform for gaming.