In that case is it worth getting something with Furigana (bunch of DS games had this thanks to size available + touchscreen)?
Furigana can definitely help save time with looking up words you don't know just yet, and to remind you of the readings of ones you simply forgot. And, it is easy enough to ignore them once you know the readings.
What kind of games are we talking? I've got a DS flashcart. Also I should note that my primary source of learning is DuoLingo, so I'll be learning Kanji and such one way or another.
It's hard to recommend any one specific game since I have memories (some fond, some bitter) of my early JP study with the games I enjoyed, or tried to. 黄金の太陽/Golden Sun had a limited Kanji set which helped in some ways, hurt in others. どうぶつの森e+ had a sliding difficulty scale for its pool of some 300-400 Kanji, but you really don't wanna mess with trying to dissect some of the slangy speech patterns in that game which make 100% more sense after you realize what they're derived from in standard Japanese. Pokemon Black/White has Kanji, if you can figure out what some of them are due to the squishedness... The long and short is, they're all gonna help and hurt in one way or another. Up to you which pain you wish to face, and eventually you will need to challenge them all
This is slightly outside the scope of this discussion, but it's worth mentioning anyway: Using an SRS such as Anki, much in the same way that DuoLingo (I think anyway) will drill you on things at set intervals, you can effectively turn any game you're playing into its own isolated instance of a duolingo lesson. I know that sounds weird, but if you screencap something in-game and paste it to an Anki card, you can review words and sentences, complete with context, to study. And when you see it the next time you review it, you'll have a memory of it which is that much stronger. Every little bit helps. This pic is merely an example based on the above screencap, and you can tailor it precisely to your needs/style, but...
The point is, if you're worried about stumbling through a game and not "getting" anything out of it, this may help you to get more out of it when you see things a second, a third, etc, time, and really get a chance to digest words/grammar and the contexts in which they appear.
It may not always be "useful" everyday stuff, but then again, if it helps you to play the games you like, who's to say it isn't useful?