Because I want to play CnCnet yuri's Revenge on linux and knowing that getting the game running in newer OSs is a hell, I can't imagine how would be for linux, let alone if it's even possible. If I want to play, it has to be on a virtual machine. For now I can play every other linux available CnC with its respective CnCnet installation. Red Alert 2 on the other hand, is elusive.
It finally worked, it looks like I didn't install the 3D accelerator(?) correctly. For other people that may have this problem in the future, make sure, when you install the guest additions, to install the experimental 3D Accelerator, not the one the installer recommends you. To do this, run the installer on secure mode and check no when the recommendation prompt appears. Thanks to the CnC team for bringing back to life such an awesome game.