I love that your sphere guy has a little butt. That's adorable.
The game play is readable. I could tell when I was climbing, and it was easy to understand how much stamina I had. I also liked the music that played and the effects when I was hit by a rock.
The game seems to lack a bit of polish. If you were to keep working on this, it'd be nice to see some more decorations, or even just walls around the platform. Also some kind of squishing after a fall would be cool, so the main character isn't so static. Those kinds of little animations can go a long way, even on a game with few artists.
I do want to say that I love your title screen and thumbnail designs. Those are really good.
Also, just making a game in general is really hard, you all did a lot of work and should be proud of yourselves! Well done!