Took me a while to get through the main screen. Took me some more time to figure out how to make a pick axe.
Here is how to play. Use W and A to move up and down on the menu screen. Hit space bar to choose an option. Wait for instruction screens (no skipping). Start destroying stuff by walking into it. Get rocks first, then diamonds, then you can pretty much keep destroying everything. To build your pickaxe you have to walk back to your main room, then you will see popups to hit E for regular axe, or Q for diamond.
To make the game better I would say:
Put key instructions on menu page to help navigate.
Space bar to skip through opening instruction screens.
Fix the HUD so nothing is cutoff (turn off free aspect in unity)
Add indicator to HUD tracking how much rock / stone you have.
Add indicator to track durability.
Add AI for the second player, or create a solo experience.
Remove condition to be in main room to craft, or add a crafting table to hint that they have to go to that room to build.
Thanks for making a game!