This is a very interesting concept, but all of the puzzles are very easy. Would have liked to see some more challenging levels, but it's still pretty cool mechanically. A button to speed up animations would be nice though, as it's rather annoying waiting 10+ turns for it to get into a loop.
Basic concept is very interesting. The idea of moving units around so that the fight lasts has a lot of interesting mechanical interactions and forces the player to learn the systems. However allowing players to place units kind of breaks it. Puzzles could be bypassed just by creating a small group in a corner and allowing the rest of the field to clear itself. I think with some work making puzzles where all the pieces are there, or even a limited set of pieces to place rather than just a fairly generous turn limit, would make a very entertaining piece.