Yes, it's true. I did it. I'm back in the riding business. But what did I do exactly? First, I uninstalled Outcast. Then I ran DirectX Diagnostic Tool. There under "display" you can see "DirectX features". I disabled Direct 3D Acceleration. After that I installed Outcast. Before starting a new game I chose "settings" and opted for the highest resolution (500x380, I believe it was).
In the game I didn't bought my Twon-Ha right just yet. I went to see a person who was waiting for Zelinas to bring him a Twon-Ha with two bags of rice. I helped him and delivered him his animal. Zelinas rewarded me. I bought my Twon-Ha for 140. Jump on it...and yeaaaahhhaaaahhh!!!
Hope this helps, everyone.