Good effort, certainly if you're just starting with Unity. The game design was pretty decent for the time given, if worked on and polished it could be a fun online multiplayer concept. One tip (maybe it's just me), but making a 3D project that doesn't need the default skybox, I just turn it off in Rendering/Lighting Settings (select 'none' under the environment tab). Generally good job on the game, and have fun in your further learning Unity! :)