This is cute! Fun mechanics and nice art and music.
It would be nice if the movement showed an arrow or max range so I didn't have to hunt down where 8 tiles away was! The circle also kinda blends in with the tiles.
It would be nice to move the camera with WASD (or the cursor + have the camera follow that)
Shriek is selectable while moving, then auto cancels upon arriving. Might be nice to disable the button if you aren't stationary.
I also think the level design would be more interesting gradually mixing the enemy types instead of all the same. That way the spreads and order are a bit more varied! (And of course, more maps?!)
The camera could also move to enemy position a little faster, found that it was pretty slow waiting for that for the enemy to be able to move.