viability: its viable! i found myself a little bit confused just because the controls were only available externally, and i didn't realize i could shoot stuff my first time playing (unity pulls me into a new tab without a description) so having instructions in the game would be good. props for having a menu! i think even putting the controls there would be great.
presentation: i think that having the controls in the game will definately help. a lot of the game feels very intuitive though so it helps a lot!
engagement: i was engaged, but i found myself frustrated specifically by the jumping physics because the jump felt so big.... i feel like with platformers jumps feeling a bit small is better than them feeling too big because at some points i was struggling to jump onto a pretty long platform because i would just go sailing over it...which was pretty frustrating ^^; but otherwise i had fun!
theme: i'm really curious what the art will look like since i think that will add a lot to the game!