Cool game and a fun concept! Pretty interesting story for what's happening too!
For anyone struggling with the alien:
Essentially you want to try and have the ice pawns take his poison pawns(anything that takes a poison will die anyway), you can use your first couple moves to move the ice pawns up 2 places and prevent their poison pawns from moving. (If he does something dumb like march his middle pawn into where your night can take it free feel free to grab it)
I don't think I ever took BOTH with the ice pawns, but even one helps makes things easier. After that just protect your poison pawn or remaining ice pawn as best you can