I don't believe I tried free mode. I did read through the controls, but it doesn't stick with me until I play the game. Typically I skip control menus or detailed prompts. Thankfully most controls translate, like the "jump" and "move" buttons. I can usually figure those out by tapping on the keyboard.
I did not realize what the colors did on the cube for a bit. I almost closed the game before I figured it out. I really enjoy the mechanic and I worry players may miss out if they don't have patience. I did have to exit the game and go back to the main menu to read the controls. Perhaps it could be in a pause menu for quicker access?
I may be biased, but I enjoy games that start off with small challenges that teach the controls and mechanics. I really enjoy this video by Mark Brown on tutorial design:
I honesty can't put my finger on the physics. It could just be a lack of skill. Most of my deaths were caused from not seeing where I was going as I jumped and tried to land on surfaces. I wanted to share my experience, so it is only an opinion.
Nice, I thought I figured out the projectiles :)