Great game! A friend recommended me this and I enjoyed the experience a lot. The art is 100% the highlight here, your style is delightfully expressive and you clearly had a lot of fun drawing just about everything, going by all the detail in everything ranging from the backgrounds to the animations.
I do have to wonder, however... what's up with the control scheme exactly? The buttons are sorta all over the place, and the inclusion of the mouse is completely unnecessary; the game is been perfectly playable with just the keyboard.
It's definitely not a big deal since the controls are just explained in the pause menu and there's nothing inherently wrong with them per se... but why not just go for a more standard WASD + JKL or arrow keys + ZXC scheme instead? Well I suppose I got what I wanted through the Undertale Mod Tool but I'm still pondering the reasoning behind the unusual keybinding choices.