Based on community analysis (Redump.org and TOSEC dumps), the Spanish Rev 1 likely addresses:
While pressed against a wall, press the punch button. This lures guards toward your position so you can sneak behind them.
A Metal Gear is a bipedal nuclear weapon that walks over anything not nailed down. A .chd file is a compressed container that walks over region locks, disc boundaries, and revision histories. The filename Metal Gear Solid -Spain- -Disc 1- -Rev 1-.chd is therefore a :
: "Rev 1" is an official update that typically includes minor bug fixes or slight balance adjustments over the original 1.0 release. Multi-Disc Handling
To play this file, you will need a PlayStation 1 emulator such as or a retro gaming handheld.
This is a Compressed Hunks of Data file, a format often used by emulators like MAME or RetroArch to save storage space without losing data quality.