Special Version differences:

1. Game has 4 loops, each increasing in difficulty
2. Player hitbox is significantly smaller
3. Bombs act like co-op bombs even in single player (triple damage bombs of standard version)
4. In addition to the peach pigs that give score, there are lavender pigs that give exp. The primary impact this has on the speedrun is making level 3 shot possible before the stage 3 boss.
5. The player gets a one-hit shield every time the exp bar is filled. This amounts to 2-3 hits that can be used strategically or to cover mistakes throughout a run.

The end result this has is that the first loop of Special is much easier than completing standard Batsugun. This is a much more beginner-friendly shmup.

The ship types are separated because B is much better than the other two by every conceivable metric, especially since this game has built-in autofire (for the record, I would allow autofire even if it weren't built in - protect your hands, you only get one pair).