I love this artstyle! It has a great vibe and I like the robot character. I think it's missing a few FXs here and there though, like when you jump (but the double jump is great) or dash, but otherwise it feels pretty good to control. I was a bit worried at first about the time it took to change direction in the air, but it turned out to be important later on.
Speaking of which, as far as I know, the first time you have to use that "drifting dash" is in a room where you have to navigate a sharp corner from a platform. I almost gave up right here, because I had nowhere else to go and this move wasn't taught to me and it didn't feel like something obvious to do. If I didn't miss an easier earlier occurrence then I believe it would be a good addition to properly teach it to the players. Also some popup text to explain what powerup I just got and how to use it.
One of the issues I had later in the game when it opens up after the double jump is that the environments feel very same-y so it was hard to know where I've been and where I could go to start exploring. I know the single color is part of your interpretation of minimalism but for me it kinda hurt the experience. Also, the cube enemies are the exact same color as the walls and were sometimes hard to spot.
I've encountered a big issue with the game that really made the experience more tedious than it should have been, but I don't know if it's a bug only I will encounter or if it's only for gamepad: turning the camera around was incredibly slow. Even with "Controller sensitivity" to the max. And it wasn't even consistent: sometimes it would be on the slow side but tolerable and others times it would barely move at all. It made looking around a real chore and aiming at flying enemies took forever while they could freely hit me. I powered through until the game opened up because it was pretty linear so far and the camera didn't need to move much, but once it opens up I had to give up.
That's too bad because without this issue and with a few more colors to help tell the areas apart, I think I would have pushed to the end! So good job ;)