Just to clarify something that I didn't realize before: Apparently every version of ActRaiser has a pure-action mode, although they're all a bit different in terms of difficulty. In the Japanese and US versions of the game, you have to unlock this mode by beating the game. Quick breakdown of the differences:
Japanese version: This is the original version. I haven't beaten this version of the game yet, so I wasn't able to test it (does anyone have a PAR code?), but I'm pretty sure it's supposed to be much harder than the US version. This version is available in English thanks to Aeon Genesis, so it's still accessible to non-Japanese speakers.
European version: This appears to be the best version of the game. The action mode doesn't need to be unlocked, and both the story and action modes now have three difficulty settings. The difficulty has been totally rebalanced, with certain things being done to make the game harder and other things being done to make it easier.
This post on GameFAQs goes over some of the differences. I also noticed that enemies that took two hits to kill in the US version now only take one hit in Beginner and Normal difficulty, your lives are capped at five, and you can find scroll power-ups that allow you to cast magic spells. Overall, I'd say the European version feels like the most balanced, polished version of the game, which makes sense since it was the final home console version.
NSS/Arcade version: I'm not sure which version came first, but this appears to be very similar to playing the European version's Action Mode on Beginner or Normal difficulty (didn't test it extensively enough to be sure which). There are a few differences that I noticed: The Mode 7 stage intros (where the map rotates and zooms in) from the story mode have been retained, you have less time to complete stages, and you have infinite continues instead of none (I'm pretty sure if you were playing the game on an actual NSS cabinet, it would ask for more money when you got a game over—but when you play on a normal SNES, it just kicks you back to the beginning of the stage with a fresh set of lives). Also, it's an NTSC ROM, so if you're worried about timing issues with the European version, you might want to try this instead.
Edit: I'm going to throw together a quick de-censoring hack for the US and European versions of ActRaiser. The US and European versions have improved monster sprites, rebalanced difficulty, and other improvements, but some religious iconography was censored from the simulation part of the game (see
here for more info). These graphics aren't compressed, so it should be an easy change.
I might also make some small changes to the script. It kind of bugs me how certain names are in ALL CAPS, plus I'd like to fix any typos I can find, if there are any.
Edit 2: If anyone who knows ASM wants to take a crack at ActRaiser, I have a neat gameplay tweak idea that might spice the game up. In the original Japanese version of the game, more powerful spells cost more MP, but it was changed in the US and European versions so that all spells only cost one MP. It would be pretty cool to add different MP costs to the different spells again (although not necessarily the exact same costs as the Japanese version) but also make it possible to use L and R to toggle through your different spells on the fly during the action sequences in Story Mode.
In the European version's Action Mode, you find magic scroll power-ups that allow you to cast spells. You can only use each one once and only in reverse of the order you collected them in (i.e., you must use the last one you collected first). It would be really helpful to be able to toggle between the different scrolls you collect so that you could be more strategic about saving certain spells for certain situations.