I gave it a whirl and yeah, the menus are all cursor driven so it's best to play with KB+M. Normal gameplay though is not really affected since you can just go old school and face every plant or rock you want to interact with... but I can see it helping with combat (it really becomes Zelda-like) but since you can switch control method on a fly, I can just switch to gamepad if I get swarmed by flies again. So yeah, if the dev can make the menus navigable on a gamepad, I can see this game getting ported to consoles.
With that said, an additional improvement the dev could do is to tie where the mouse cursor is to where the character is looking. Interactions will make you face that way. In the case of the gamepad, the right stick can allow you to interact with things diagonal from you. It would in a sense bring the gamepad up to parity with KB+M. With how the game visual is ran, it wouldn't look weird at all.