Noticed that the music in the ending of MG1 is playing wrong. It cuts off somewhere and then starts playing again.
Listend to the ending wave file in the sound directory and this one plays fine so its something in de code itself.
Notice also during playing the game that the punching action is versy slow compared to the MSX version.

i got the old instruction bookie for this game. you maybe wanna have the pictures how it lookted like?

They added optimized controller support. This description is from the Metal Gear Solid changelog:

Update 1.0.CU (27 August 20221)

Added full support for many popular modern controllers (including Sony DualSense, Sony DualShock 4, Sony DualShock 3, Microsoft Xbox Series X/S, Microsoft Xbox One X/S, Microsoft Xbox 360 Nintendo Switch Pro)

Optimized default key binding

fixed trigger buttons not working properly