The romname says "earlier" but this is not the case. This romset is the proper PCB of daioh, the "parent" rom on MAME is a romhack that was submitted claiming to be the newer version.
carrying on.
Daioh is a shmup by Athena, the goal of this movie is high scoring, specifically "anything above the counterstop of 99,999,999"
The true score of this run is 108,362,740 it could be a few millions higher but this requires boss manipulation that is currently not known OR makes sense + rng manipulation that there is no method for. My target was 106,000,000 so this is pretty ok.
Scoring comes down to a few factors;
1) boss1. Boss1 has a bug when it's at 16 or less hp, bombing the bottom right corner will award massive points. 800k with a laser bomb, 1.2m with a missile bomb. The target was 25 million per boss (2 loops), 26.5+ is theoretically possible.
2) Excess powerups : each powerup/speedup/yellow orb/bomb at 20 bombs gives 5,000 points- bombs will also give 5,000pts * bomb stock at the end of each stage.
3) tick points with the lighting weapon, self explanatory!
4) excess lives at the end, each spare extend is worth 800,000 points at the end of 2-7, so extra lives are manipulated to spawn via the item counter (this ticks during bosses and every powerup that spawns)
Daioh also features a really intense rank system, with a near limitless ceiling on the games difficulty. I aim to have this go as high as I can manage, which makes for some pretty fun moments in the movie.