Good job, the mechanic have very potential, you must be play to place a charactes in the air, or place a mechanic that make a stop a character in any position during 10 seconds, after that, the caracter's gravity has restore and if was in the air, fall to the ground.

A good game, it's very adictive to play, only one fix, instead of drag and drop for select aliens, could be better only click to place or remove from the ship.  Good Luck.