I'd like to see what you all are talking about here with the respect to whatever RPG maker is in reference to FF4.
Is it a game or some kind of software? I recall having an old PlayStation game about 10 years ago called "RPG Maker" but I didn't find it at all interesting and gave it away to my cousin. I guess some successive generation of this thing is around?.
Now to me, looking at the graphics in the PSP game (absent the above bias) they are all very evidently derived from the original SFC and upgraded WSC graphics. And I'm pretty darned familiar with how this game looks across all it's versions as I've generally played it once or twice a year for the last 20 years in various different versions. The first thing I see is that the tiles obviously have a much higher pixel depth than any of the previous 2D versions because of the available hardware. Instead of 8x8 tiles they appear to be 16x16 (or things are made up of 8 tiles rather than four) so the graphic designers have been able to add more detail. Really it appears that someone sat down and took all the old tiles and bumped up the pixel resolution. In fact it appears that a team of graphics artists had to rebuild the entire tile set for the PSP game. Besides this if you play through parts of the DS game and then go back to the GBA or WSC game, it looks like they blended the two. They seem to have added some of the detail from the DS game's location maps to the 2D maps in the PSP game. However they've kept the location maps very faithful to the original SFC game. So honestly, If this RPG maker software you're all talking about has the exact FF4 tile sets in it, or ones so close it's stupid, I'd like to see that.
I also happen to like the new styles on the sprites and the in-battle magic effects. All the character sprites seem to be following the design sensibilities used for the DS game, which have been the most faithful to Amano's original artwork. They all also have a higher pixel depth so they have more detail. Something I think the map sprites in particular sorely needed...those old 4-tile 16x16 pixel sprites in the previous 2D versions were always too basic for my taste. Furthermore the spell animations are pretty spiffy IMO as well. I like the flame effects on the fire spells especially. Monsters have also all been upgraded in look with either completely new artwork in a few cases or just higher pixel depth detail. It's nice to see something new and different in such an old game.
Besides that in my opinion it just generally looks pretty good, especially compared to the old SFC game and even the GBA game. I guess if this is what stuff looks like in whatever RPG Maker is, so what? If that's not enough to warrant buying it again nobody is advocating that, at least not me. I mean this game has so many damned versions its stupid... It's easy to pick the one you like.
Having said all this I don't think the PSP version of FF4 is the end all beat all. Importantly I think this version is far to easy; the difficulty and balance in the DS version was much better. It's been some time since I did a full playthrough of the GBA version but that also seemed to be a somewhat harder game relative to this PSP version, but not as difficult as the SFC original or the DS game. I also seem to be one of the few people that liked the "flowery" translation used in the DS game. That seemed to disappear. However I know a lot of fans that did not like the DS script at all and are very happy it's now "gone".
What I like best about this PSP version and not any less about the GBA version are that you can party swap at the end of the game. While the bonus dungeons are nifty, really it's mostly that the party swap for me is a huge feature. I like it a lot, and it was one of my favorite features of FF6. Actually I wished there was more of it. In fact I think the original SFC game probably intended to use it but it didn't get done. I missed it in the DS game and I also didn't particularly care for the augment system in that game as a workaround.
A hardware related thing I like about the PSP version is that I can output the audio and, importantly, video to something else, like say my 55" plasma and my home theater surround system. I can also do this with the GBA game using the GBA player on the GameCube. Of course this is also an option for the SFC game, especially if you emulate. However having to only use the damn handheld to play the DS game pisses me off. I even got one of those huge DSi-XL things and, while much better, I still prefer to hang back on the couch with a controller rather than be hunched over a handheld. Why Nintendo can't figure out how to dump the video out of the top screen and allow the controls and bottom screen of the DS to act as a tethered controller for a larger monitor makes no sense. In my opinion Sony got that feature way right on the PSP.
Another hardware positive is the Audio on the PSP is great; both the original SFC score and the "arranged" score are clean and high quality. The GBA and DS sound output is atrocious and grating. I mean I can barely stand to listen to either, I recall turning both way down to just audible enough to know what was going on. This is another win for me as I continually went back to the SFC versions (generally via emulation) for play through simply because they sounded better.
Anyway the DS game is a much different version all around than any 2D version of FF4, so the DS game stands alone as a version IMO. I'm comparing this PSP game to the other similar 2D games, which are all more or less the same essential game -- difficulty, graphics, and bonus features notwithstanding.
Like I said earlier there's no reason to really go back to the GBA game from this version, the graphics are improved IMO and the audio is 1000x better sounding. However I can see where you could pass this up if you already have the GBA game and don't care about The After Years, especially if you'd have to drop the cash on the PSP. Furthermore if you really liked the DS game over other previous versions I can see this one as a step back, in which case I wouldn't recommend it at all unless you have a PSP and you do want the After Years stuff.
We have EVEN MORE themes now, but some old ones are gone...