Having just completed Nanashi no Game due to a translation patch (sorry, I cannot link said patch here, but you should be able to find it easily enough by searching, if you are interested), I'm actually left with rather mixed feelings... But before I get into that, I should explain what the game is for those who have never heard of it.
Nanashi no Game is a horror game on the DS. The plot is fairly simple: Rumours have been circulating about a cursed TS game. The rumour is that anybody who plays the game and fails to complete it within 7 days will die. You take the role of one of the games players, having had a friend recommend it to you, however you soon discover that there may be truth to the curse; Upon visiting said friend, who had been playing the game for 7 days, you discover that he is dead. Having discovered this, you begin to try and find a way to complete the supposedly unbeatable, cursed game.
The gameplay is split into two sections. One is the first person survival horror set in the real world. To move about in this section, you hold the DS like a book and use both the directional pad and stylus (tapping the center of the screen while pressing up (or right, rather, but since you're holding the DS like a book...) makes you run, tapping the sides while pressing left/right (or up/down, if you prefer) will make the view move faster in that direction. The other is the 8-bit RPG game world. The controls are what you would expect here: D-pad to move, a to talk and examine. The two sections actually work well together, and perhaps make the game more interesting than it would be otherwise.
Unfortunately, the game is quite linear in both sections. Moreso in the "Real world", as there are several items hidden about in the game world (you actually need to collect certain items in the game world in order to see the "Good" ending), however the "Real world" is largely just "Go from point A to point B. Look at the one (or several) items you went to the location for and escape alive from any ghosts that show up." To be quite honest, it feels like there was quite a bit of potential that just wasn't met (most objects in the real world can't even be examined).
Another complaint that I've seen is that the save points are too far apart. The counter to this would be that you can actually save at any point in the game, providing you don't mind suspending the game. Although I was unable to continue a suspend save (my console froze when I tried to), it could easily be a firmware issue, and not the game or patch's fault. That said, each day is fairly short, and it's likely you'll end up completing the area before wanting to save anyway.
There is a point in which the game is considered by many to be outstanding, however. Namely, the audio. In fact, even though many of the game's scares are cheap, "Jump scares," I have to admit that the game did manage to make me jump at one point, which is more than I can say about most horror games these days, unfortunately.
Overall, if you're curious as to what kind of survival horror game that the focus group shot down (apparently because, "You couldn't shoot anything,"... I REALLY hope that is not truly the reason) a possible NA release of, or just want to see how the game-within-a-game mechanic plays out, it'd be worth giving Nanashi no Game a shot. If you're just looking for a super scary game, you may want to pass. If you DO decide to play it, will you be able to figure out the mystery and beat the supposedly unbeatable game within 7 days? Or will you just become another victim of the curse?