Sharp, buzzy FM synthesis straight from a PC-98 sound board. Gakuen Triangle is a PC-98 game, and the soundtrack comes in two flavors: OPNA and OPN versions of every track. "Battle Music of the Colorful March" has this driving, almost triumphant energy that the OPNA version renders with noticeably more depth.
Read more
"Tension" does exactly what you'd expect, tight and urgent. "Dimly" pulls things into darker territory with a slower, moodier arrangement. Having both sound chip versions side by side is genuinely cool. You can hear the extra channels the OPNA adds, the fuller bass, the richer tone.
Pure late-80s/early-90s Japanese PC sound. That distinctive Yamaha FM crunch that nothing else replicates. One for the FM synth nerds who want to A/B compare sound hardware through actual game music.