This probably isn't worth playing because I only implemented the very basic mechanics.

Controls:
WAD or Arrow Keys to move, can also jump with space.
Press o to fire projectiles
Press the period key to switch the focus of the camera on the bottom screen.

Currently there is no way to win, but two ways to lose. You can lose if either your health or your castle health reach 0.

Non-gameplay related if you press F8 you'll enter the level editor. From there you can edit the level, but the controls are strange. Also, I didn't implement saving correctly, so no changes you make will be saved. It's still fun to play around in though.
Level Editor controls:
Arrow keys left and right to cycle through placeable tiles/spawn points;
[] to cycle between placing tiles and placing spawn points
T to switch from top world to bottom world
V to save changes
F8 to switch back to play mode. Fair warning, there's no input delay on this so you'll probably accidentally cycle back and forth between level editor and play mode.
Each level must have a player spawn on the top world and a castle, ally_spawn, and at least one ally_caster on the bottom world. Otherwise you get a NullPointerException and will have to redownload.

I plan on continuing to work on this game in the future, so if your interested check my website (http://www.manicthenobody.com) in a month or two and I'll probably have some updates. Right now that place is a wasteland.