"With the amount of grinding this game requires, playing it for just a few minutes at a time is likely to mean that you'll be playing it for months before you reach the final boss."
In the world of gaming these days, there are a lot of dark and serious games. For emotional impact, they're great, and they can show off some of the medium's true potential as an art form. That said, I'm glad that's not all there is to gaming these days, because as with film, TV, and books, the medium's also got great potential for being simple, light, and fun. This latter target is the one Rainbow Moon aims at... although it doesn't exactly hit the bulls-eye.
In Rainbow Moon, your character has been thrown through a portal to another world by his rival. Mysteriously, your arrival has either coincided with or caused the arrival of monsters everywhere in this other world, and if you ever want to get home, you're going to have to do something about them. That's the setup, and unfortunately, it's about as good as the story gets. The game is essentially a series of fetch quests, some segments of which are fairly annoying. There are times when you hunt down an arbitrary number of MacGuffins before the current gatekeeper lets you proceed, and other times when you simply run back and forth between a pair of NPCs relaying messages for several minutes. Not exactly gripping.
The gameplay suffers from similar issues — it isn't conceptually bad, but it relies too much on grinding. Battles are fairly standard strategy affairs in which player characters and enemies take turns punching, shooting, and casting spells at one another. Completing battles nets all participating characters experience, as you would expect. However, each time a character kills an enemy, they also earn Rainbow Pearls used to increase stats as you desire. You can't use this method to turn your tank into a speed demon, but you can at least make your own choices about how your characters grow, which I always appreciate.
I also like the way you encounter enemies — there are monsters visibly wandering the map, generally blocking your way to a treasure or your next destination, but you also get alerts that let you enter optional random battles. This allows you to pick your battles, so while you're required to do a significant amount of grinding, you get to avoid the terror of being attacked by a group of random enemies while you're running back to a healer on the brink of death.
For me, the copious amount of required grinding grew tedious relatively quickly. However, should you feel differently, Rainbow Moon is the type of game that you can play as long as you like. Reaching level 80 should be enough to get you past the final boss, but by the time you're level 10, you catch a glimpse of enemies who are as high as level 800. Rainbow Moon was originally released on the PS3, but this type of longevity and grinding are much better suited to a handheld platform like the Vita, on which you can pick it up and play it for exactly as long as you wish.
Speaking of this new incarnation, Rainbow Moon's controls have been tweaked just a bit for the Vita. Battles are still based on the standard, diagonally-oriented strategy RPG grid, but now you can use the left analog stick to move rather than using the d-pad. It's a small change, but a nice one, since it helps you make sure you walk or attack in the direction you really intend. I was, however, often frustrated by one specific control issue: there's no undo. I'd accidentally take a step I didn't mean to, and boom, wasted turn. And when you don't like grinding in a grind-heavy game, a wasted turn can mean death.
Rainbow Moon's presentation translates well to the Vita. The bright colors and sort of anime-style characters are clear and nice to look at for hours, although I'm a little disappointed that many of the enemies are simply palette swaps of each other. Likewise, I enjoy the fact that both PCs and NPCs have some voice acting, but the lack of variety in what they say (and for some NPCs, their unintelligibility) is disappointing. The music, on the other hand, is a high point — it's not the greatest music I've ever heard, but it's notably better than I expected it to be.
If you played Rainbow Moon on PS3, I see no reason to play it again on Vita. However, if you didn't, there's fun to be had here, particularly when you consider the $15 price tag (as of this writing). The Vita is a great platform for a game like this, where you can pick it up and just play for a few minutes before moving on. That said, with the amount of grinding this game requires, playing it for just a few minutes at a time is likely to mean that you'll be playing it for months before you reach the final boss. Whether or not that's a good thing is up to you.