Briefing
Why it is hereField Notes
3 things that are not obviousThere are more than three campaign missions
They unlock as you go. Finishing the last campaign mission unlocks a few other playable mecha and vehicles — each one plays pretty radically differently.
You can command friendlies RTS-style
Aim at a friendly and scroll the mouse wheel up twice. That brings up a map where you can drag-select units and give orders with the right mouse button.
The game is not alt-tab friendly
Don’t switch away mid-mission.
Acquire
Free downloadHigh-MACS Simulator v1.0.5f — mirror
The last public build (2017-05-23), hosted here directly. ZIP, 119 MB. Byte-for-byte identical to the official download. Unzip anywhere and run high_macs_sim.exe; the archive includes a readme.txt from the developer.
English manual
The developer’s own English manual: default key bindings, how radar detection works both ways, and how to run the tactical map to command your friendlies. It is not in the download — the game ships with a Japanese readme only.
Official site — offline backup
The developer’s site rebuilt from the Wayback Machine so it browses locally: both manuals, the surviving tips page, screenshots and styling. ZIP, 1.3 MB. See ARCHIVE-README.txt inside for what the Wayback never captured.
High-MACS Simulator is the work of grape65535 and is mirrored here as freeware. Gungriffon is the property of its respective owners.