Feel free to use any of these sprites in your own projects, if you find a use for them. Also, check out my other projects if you would like to see these sprites in action. You can drag the sprites around in the player, however some sprites have multiple costumes, so you'll need to open the editor to see them.
For @12Three and I's collaboration, here is a compilation of all my hand-drawn sprites. Update: That collab never got off the ground. However, 3 years later I'm uploading this "amazing art" at the request of @SpaceX24. Some of the sprites featured in this project have never before been released, as their projects were cancelled (see "monster" sprites)!