I will definitely give Unity a go in the future!! It just seems super daunting to learn a new engine especially Unity since it's a massive engine compare to gamemaker haha but I know basic C# so hopefully it won't HARD!
In the meantime, I'll might able to Linux port for gamemaker next week or so. Either that or I'll try to re-make this with Unity. Either way i'll let you know, but a Linux version is available :D