The game is create with GameMaker Studio 1.49, i don’t plan to release the source for the moment.
But you can look here :
https://itch.io/c/3094616/robowarriors-source-code-collection
Specifically the BOMBER ZONE code source, there is with 3D basis into it.
Other information the first version of the game was originaly created for Ludum Dare 53, if you’re interested by learning or just code source of games, you can look on the Ludum Dare website, the games published in compo mode have their code source with them.