Really cool artstyle here, fun and the movement mechanic is pretty smooth too. Got stuck on the area after you defeat 3 enemies though, not sure how to unblock the gate.

The Linux build there is the 32bit version.  You would want to do the x86 + x86x_64 (Universal) build from Unity.   

This was great! Nice graphics and except for the boxes sticking to the wall sometimes, very smart gameplay that was fun to unravel.