Love the Achievement Unlocked style and the UTDR references were fun too. Really fun to try to figure out and unlock everything and the cannon jump felt nice.

Just some minor issues with the gameplay, dropping through platforms feels a bit slow . It would also be better if there was either some kind of buffer that lets you drop through If you pressed down just before landing or just having it so holding down lets you drop. I also noticed you can still collide platforms from the side at specific heights. Though this never affected the gameplay too much, it did feel a little clunky whenever it happened. Also, when playing with WASD, there's no real equivalent for playing with arrow keys + zx so I was kinda just forced to use space to jump or to swap over when trying to shoot so adding k to jump would be good.

 I don't want to repeat from others too much, but I think adding, extra achievements and being more self-contained would benefit the game. Additionally, I feel  having more leeway could allow for esoteric or hidden secrets like in Deltarune though there maybe some issues with needing the player to learn certain mechanics if they get the extra stuff. I think it would also be nice if there was some way to sort the achievement list to show what is currently still locked. 

Overall still a very fun game.