[x] Squares
They spin at you in a way the lets you run them in circles, but they're kinda tanky.
[x] Snakes
Worm-like creature with a large head and diamond-shaped body parts. They move in sine waves.
[x] Arrows
They can only move in the direction they're pointing, and constantly try to point towards the player.
[x] Blobs
Explodes into smaller versions of itself upon being hit. This process continues until its parts are too small.
[x] Gates
Two small nodes with a line between them. Comes at your horizontally. Nodes are weak while the line is strong.
[ ] Slicers
They fly towards you, and once close enough stand still to charge for a moment, after which they zoom really fast in the direction they were aiming. You can see a laser showing where they're about to slice.
[ ] Gridsnakes
Similar to snakes, except they can only move on a grid. Made of squares.