Be prepared to be spend a lot of time with your 'X' button and loathe the fact that there are no mid-level checkpoints.
The gameplay here is as simple as it gets. You run around with your characters, slam on the 'X' or 'Y' buttons, & kill enemies. For each enemy you defeat, you get little red orbs. Once your red orb meter is full, you press the 'B' button to unleash a pretty cool attack. For every enemy you kill while doing that attack, you earn little blue orbs. Then once you fill up your blue orb meter, you can then unleash a area-sweeping mega attack. That's about it. Every so often you will have to jump or block, but that button-mashing is about it.
It goes without saying (but I will anyways), this type of game has the tendency to get boring quite quickly. The only thing that is keeping you playing is the story (which is o.k.), the different characters (some are fun & a couple are terrible), leveling up your chatacter (very basic, though), and finding items. Other than that, there isn't much reason to play this game unless you are after the very time-consuming achievements.
My main problem with the game, other than the boring button-mashing combat, is the fact you can't save the game mid-mission at all. This is EXTREMELY frustrating while using some of the later characters. Some missions can take quite a while to play through and then you get to some end-boss that kills you with some cheap (and unblockable) combo in just a few seconds. That means you are starting that mission from the beginning. This is, EASILY, my biggest pet-peeve in gaming. I hate developers who are either too stupid or want to superficially extend their lame game by making you re-play levels over and over just because they don't put in adequate save points. Ridiculous.
At least most of the characters play differently. There aren't a ton of missions for each character, but I thought that was a good thing. The game gets repetitive enough with the combat, so it's nice to use a new character sooner rather than later. The terrible voice acting that comes out of these characters mouths, however, is enough to make you want to play this game with the mute button on.
The music in the game is great, but the voice acting really takes you out of the experience many times. A couple of the characters aren't too bad, but most are terrible and some of the lines they say are even worse. If it wasn't for the musical score, I would have given the sound a '5' or '6' in the rankings.
Ninety Nine Nights does look a lot better than the Dynasty Warriors games. Of course, this isn't saying much. The cinematics in the game look outstanding. And I love how they got so many enemies on-screen at the same time. The problem is that there is some slowdown and the in-game engine visuals don't exactly scream "next-gen".
Overall, I think Ninety Nine Nights would be an o.k. rental.....at best. It really is fun for awhile and if you really dig the combat, you might get into it longer than I was able to. I just lost my patience with the lack of checkpoints, idiotic A.I. of your fellow soldiers (I won't even get started on that.....), and the constant button-mashing combat. It's too bad Phantagram didn't try to take this genre to another level here. Instead we are left with a better looking Dynasty Warriors clone that serves better as a rental than any sort of purchase.