That's great! We really appreciate you! Please write it here to let others also see your nice feedback. That would be useful for us and other players, definitely!
Filaipus already mentioned most of my issues, as we've talked a bit in a different place, so I am just going to focus on the design aspect. I'd second any of his mentions (especially the text adjustments) and also throw in another mention of playing around with pixel/voxel graphics for the main character and potentially rebranding the game name. Most people looking for this type of game are primed to look for "Runner" names, maybe something like "Void Runner DX" or whatever, just a random idea, but I highly suggest finding a different character style first and then brain storming new brand ideas.
I would also really suggest you work with very simple blown up pixel graphics and try to get a first version up to see how you like those (there are plenty of free pixel/Voxel assets out there)
They might not even need to be fully animated, just a 2 step animation might be enough (think the first bit trip runner or the little character from the game and watch series)
Actually, you might even get away with trying entirely 2d pixel assets as well, as the game is relatively flat anyway. Do play around with those! That would also allow for an endless amount of fun unlockables that could be simple assets.
I was already thinking of offering the Steam release fee as well, but I see filaipus also had that covered ;)
Do keep us in the loop please. I want to see where you guys take it from here and would love to playtest some more when you come up with a new version or you need some opinion on character design decisions.