You can play Mental Omega on any version as long as you have gamemd.exe from 1.001.
Even if it says 1.0.1.1, it's still widely considered 1.001 by Syringe/Ares, except edited for Steam/EAApp.
This difference is only for the Steam/EAApp updated releases, which require a compatibility fix we are now testing at our Discord.
For the time being you can find it here, in the support_solutions section: https://mentalomega.com/discord
It worked, thanks.
The game loaded, going to play and check if everything works