Out of the modes that feature 1 hit kills (and are generally appropriate for people well versed in tougher shmups), this is the easier mode. Attack patterns are a mix of loop 1 and 2 attacks from the story mode's Ridiculous difficulty, but enemies have considerably less health, meaning it's easier to clear the screen of large, nasty enemies. One other change is the enemy in stage 5 that shoots at you from the background does not give massive quantities of energy tanks for absorbing his shots, so you have to carefully select your upgrades according to your tastes.
Stage 1 only allows for loop 1 weapons, and stage 2 onward lets you select everything that'd normally be locked to loop 2. I get two bits in Stage 1, then immediately save up for the Non-Stop weapon, which is both very powerful (roughly as strong as Twin Wave) but also has the unique effect of shooting even when using the shield. This gives it INSANE damage potential when absorbing continuous attacks, and is very safe to use against popcorn rushes where you'd otherwise have to frequently stop shooting to absorb the revenge bullets.
Perfect Guard is a nice shield to use, but because Arcade Hard is a 1 loop game, there's not many energy tanks to spare. Going with Auto Guard gives you a 5 hit energy shield, and frees up those 7 energy tanks for other things.
Nearly died at 6:35, oops. I'd been playing this nonstop for like a week trying to get a deathless run, it figures I have a very silly near-miss by accident on a run that clears it. Now to see if I can finally no death clear the Ridiculous difficulty (which has higher enemy HP and 2 loops).
The modes that depower you down by 1 stage on hit are pretty forgiving but they're a great entry into more complex shmups for beginners.