Hey Ross and Forum. I've dove deep into tough as nails arcade shooters; the type of game Ross tends to avoid. I've 'suffered' for you and found some of the best music that hasn’t been mentioned here yet. Bad sound emulation has also plagued the arcade scene, so I’ve tried to Here's some hits for starters:
Soukyugurentai OST - Intense Cold Oil Field Base
Mushihimesama Futari OST - On the Verge of Madness
Battle Bakraid: Terrible Object
(Listen to KHI if possible, youtube uploads are trash quality)
So there's this guy named Manabu Namiki right - and he's the best video game music composer you've never heard of...
Battle Garegga - Subversive Awareness
Desert War - Mission 1
[!] Many online rips of Desert War arcade are poor quality and or missing sound channels due to incorrect sound emulation. This link seems to be more acurate to what the arcade PCB produces.
DoDonPachi Dai-Ou-Jou - Mixed Mellody
And here are some more other random shooter jams that are obscure enough average people would probably never hear them.
In the Hunt: Sega Saturn ver. - Stage 1
https://www.youtube.com/watch?v=Si944QJcWHg
Neko Navy OST (2017) - Signal Red
https://www.youtube.com/watch?v=ovIrlc1nY00