I love the charm here, everything looks just lovely. The textures are small and smeared out over large surfaces, the mole is appropriately chunky and exhibits a dorky bounce as they walk around the hub, and there's a decent amount of resolution crunch on the final output. It all looks a bit fuzzy, and in the best way.
I will say I ran into a few issues when playing. The difficulty spike from level one to two was quite a wall, and it took a lot of attempts to finally clear it. The aim on the gun is wonky and I could never quite suss out how the position of the onscreen cursor correlated to where in 3D space the shots would actually wind up. Aim was very slow on a controller stick so I had to swap over to mouse/keyboard to clear level two. The rate of fire felt slow unless I was really mashing the button. And a few times the minecart wound up with some odd offsets from the track, either a slight displacement horizontally or, on one occasion, a fair distance above the track. I suspect it's due to how gravity is implemented, and how the grace period is granted for swapping lanes when your current track has already ran out, but that's all just conjecture.
Overall I love the lighthearted vibe here! If you wind up implementing the boss I'm curious to see how that fight plays out!