Very cool OST indeed, and also just a cool game. The handling of the mechs is so satisfying, and the controls are so smooth, even the many
100%/infinite combos are easy to forgive. IIRC, every suit has them? Certainly most, which created an odd sort of balance. I can remember discovering the game in a ROM folder and it quickly becoming a minor favourite in my circle - we'd basically figure out the most broken stuff possible, then airdash around trying to be the first to land that fatal hit and subsequently light the enemy up like Christmas. Fun combo of high maneuverability and brutal punishment. Maybe more Hokuto no Ken than Gundam that way.
No mistaking the sense of piloting a hulking-yet-agile machine though.
I'd kill for a Ninja Warriors Again/Assault Suits Valken brawler/shooting hybrid using that engine. The booming presentation and mighty heft rival anything from the subsequent console generation, including Natsume's own Gundam fighters. Hell, this thing came out in 1996... technically it really was going toe-to-toe with the PS1 and Saturn's 2D offerings.
Heavyarms BGM was always my favourite, too. The stage rocked as well... I seem to recall that and Deathscythe's being my two favourites. They all look great, with some neat city/space/pastoral scenes, but it's those smouldering industrial warzones littered with ruined vehicles and aircraft that I really dug.