Well...
You should've made levels/stages like... 1st stage there's one red sphere after you & one bouncing blade... then more come in the next stages... the music of the menu almost gave me a heartattack... try adding calmer music... a bigger area for the blue sqare to move around... less electric floors... stages... slower movement... and that's just about it... for a very simple game you could've made it have better graphics and gameplay... but still a solid job... keep up the good work!