I tried your game - I think you have a lot to learn when it comes to optimization of assets. Your game has really low fps, but that's not only fault of the gameguru engine;
You are using very heavy textures and lots of polygon collisions - that's a huge performance hog.
There's a very good tutorial about texture optimization on gameguru forum: https://forum.game-guru.com/thread/222504
Collisions can be pretty tricky too, as theres alot of different types good for different occasions, but in general it's good to avoid polygon collision whenever possible.
You can set it up in fpe file of any asset, try it if you have some time, it makes big difference :)
unfortunately ive lost the games source files as my hd, where i had it stored broke down :/ But if I manage to rescue my data somehow, which ill be intending soon (need money for that), im going to overwork the game and bring V.1.1
meanwhile you can check out my game grave digger if you want it has better performance and im overall more confident with it then with RUN! :)