Very cool idea and well designed, but it would be nice to have more distinct visuals for the enemies and hostages.
Initially I wasn't sure why I don't get a full score when moving and stationary enemies kill each other, on level 8 it says "Enemies killed: 4/7", then I realized that technically I shot some of those enemies before they could get to the others. Adding some kind of marker to the timeline to show the order of events (such as a standing enemy getting killed) would make it way more intuitive.
Still a very unique and surprisingly complete game for this jam.
Edit: I also noticed that overlapping enemies cover each other completely. If two enemies are on the same tile it would be nice to have an offset between their positions.