StrikeforceInfinite
This is open source under the MIT License. You can obtain the source code from Strikeforce Infinite
Strikeforce Infinite is a 2D space fighter game written in C# (currently .net8) and rendered with DirectX. The game features infinite space, neural network AI, multiple scenarios, single-player, multi-player, locking/seeking weapons, a "speed-scaled" environment, dozens of weapons and massive fiery explosions...
Check out the alpha build 13 gameplay on YouTube: https://www.youtube.com/watch?v=Kd-aEshWiNg