I would suggest against GMDX for a first time playthrough, it changes A LOT. From the aesthetics, to the gameplay, to the sounds, the mood, the feel of the game, and the viable approaches in each level, there’s so much that’s changed it just isn’t the same game anymore.

You’re much better off with the Vanilla Fixer tool, Transcended, or Zero Rando (I’m the dev). You could also use Revision and toggle every setting to vanilla, but make sure you also disable the HDTP models, and disable Shifter and Biomod too.