I seem to be getting the bug where its not saving the map, I'm not sure how it gets into this state, but this is what I'm seeing
Any walls I place ARE saved, any players or enemies are NOT saved
I tried these different scenarios:
walls > players > walls
players > walls > more walls
walls > walls > player
walls > player > build map and see the player is where I put them
In each case, as soon as i left the map and came back, the walls WOULD save, but the player (and/or other entities) WOULD NOT save
In any case, great work, I think this is gonna be a great engine, keep it up!