Just so you know, it's not possible to actually make modifications to the game. It was made with Multimedia Fusion 1.5. I don't know what things are like currently, but back at the time where the software was known as Clickteam Fusion 2.5, it had no support for MMF 1.5 extensions, of which this game uses quite a few. You'd need to track down a copy of MMF 1.5 in order to be able to actually compile the source code.