I think the overall look of the game is good with the low poly and robot stuff. I only made it to the start of the 3rd level so I only have feedback on those areas.
Progression in platforming difficulty seemed mostly good, the switch to 2D for the 3rd level was unexpected but I think was kinda neat.
I liked that there were actual checkpoints, and the little crystal would light up and float.
There seems to be collision missing from several game world objects, specifically in the first area you can just walk through the trees, the checkpoint signs, and the little tent.
The combat so far could use some juice since its currently just a little jab, a more expressive animation could be something cool to add in later versions.
The hitboxes on the moving saws on the ground are definitely off, I was standing in between two of them and even though my character was clearly not touching the saws I got damaged anyways.
And maybe this is just me but in 3rd person platformers I always like it when the player character has a blob shadow directly underneath them. So it can be used for aiming jumps like in Mario 64, I even implemented it in my FPS game lol. But your mileage may vary.