That's just the co-op mode. It's a full fledged MGS written and directed by Kojima.
If you want to play a more detailed MG1 hit up it's original edition on the MSX, it's not much different to the NES version save a few battles and the graphics. It's also translated better.
hey crosell. i just wanted to thank u, og, sl, fmp, and ryush for what you've helped me threw in solar and lunar. If i ever get the time i'll see if i can work on it again, but i simply don't, just wanted to thank you again for all the help and support ya gave to the semi-decent project.