Hi Dinamic Creates, thanks for the feedback!
I think I will write in the game description the menu controls, I didn't think about that at all >-<. About the monochromatic style, I love it too! (centainly Downwell was the game that introduced it to me, I think) and was also one of the optional conditions of the game jam I made this prototype for, so it was the perfect chance to try it myself.
I only had 3 hours (it actually took me 4) to develop the game so I couldn't make more levels :P. However I liked how this one turned out being my first published project so I think I'm going to make more levels and implement some more mechanics in the near future as well.
If you have any other suggestion or critique feel free to comment it. Learning from feedback is one of the best ways to improve in the thinks we like doing!
Again thanks a lot and I wish you success in this heavy yet wonderful place we call videogame development. (Sorry for the wall of text by the way, I don't speak English natively so my redaction can be a bit messy.)