Tiny Planet Defense is a tower defense game, where you place weapons around the orbit of your planet to defend against an alien invasion.
We made it within 72 hours to the Ludum Dare 38, using MonoGame and MonoGame.Extended. The best part of the development was that I had no idea how to use shaders and learned a lot with this game, applying it on the damage effect (white flash) and two as post processors (scanlines and the Bloom Filter from @kosmonautgames).
Other interesting stuff is the pixel collision, that I archived to make it work with an animated spritesheet, rotated and flipped. First time making lasers too. All the source code of the game is here: https://github.com/Phantom-Ignition/LudumDare38
Be aware that the code is kinda mess, I had no time to do things the "correct" way
Ludum Dare page: https://ldjam.com/events/ludum-dare/38/tiny-planet-defense-1/