I love games that use the Apocalypse World system. At Metatopia I playtested a bunch of AW-bsed games, ranging from relatively straightforward transpositions of the mechanics into new scenarios, to wildly creative reimaginings of the system. It's my go-to system for a more traditional* game.
So when I design a game, it's worth asking why I am, or am not, using the AW system as my basis. The two games I brought to Metatopia make a good illustration of this, since one is AW and the other is not.
My AW game, tentatively titled "Get Ready to Rock," is about a band on tour. It was inspired in part by some sessions of the "Touring Rock Band" and "Touring Rock Band 2" Fiasco playsets -- so I know that you can tell the kind of stories I wanted to tell without AW mechanics. And my use of AW started in part simply from noticing the similarity between the name "Apocalypse World" and the name of the show "Metalocalypse" (another key inspiration). But the game has progressed and worked because the AW system does certain things that are useful for the kind of stories I want the game to produce.
First, one of the key drivers of the game is the tension between the cohesion necessary to play music together, versus the clash of egos that arises when a band hits the big time. This is supported in part by some of the base AW mechanics. The use of differentiated playbooks geared to different roles in the story helps to model both the complementary differences that make a band work (made obvious in the formulas used by music executives constructing boy bands and supergroups), as well as the different directions that each member's personality will tug the band in. I also borrowed the "strings" mechanic pretty directly from Monsterhearts (which I regard as the paradigm of an AW game, perhaps even more so than AW itself) as a way of intensifying the need to make complicated choices that implicate your fellow band members. I also implemented one innovation which followed smoothly from the AW base: the band as an entity has its own playbook, separate from the players' individual ones, with its own set of stats, its own harm track, and moves that can only be done by the band as a whole.
Second, I wanted the game to motivate the characters to make bad decisions and get themselves into trouble. This is not a game where the GM dreams up a set of challenges that the players then work to overcome -- instead, the characters' own actions should get twisted to draw them further into complicated situations and force them to make difficult choices. The aforementioned strings are an obvious way to do this, and I enhance their role in the game to allow players to make things complicated for each other. But even more importantly, the "partial success" mechanic in AW leads directly to complications. Having clearly structured "moves" means that players are confronted with tough choices and a framework for complicating their own lives when they roll anything less than a 10.
On the other hand, I think there are good reasons that Laser Kittens is not an AW game. For this game I developed my own system, based on bidding cards from two standard poker decks. There are several aspects of the gameplay that I wanted, which would be difficult to model using an AW basis.
First, Laser Kittens is a game with a rotating GM. Now, I know there are GM-less AW games out there, so it's not an impossibility. But it doesn't follow easily, because there is a tension between the player-level decisions involved in bidding to GM a scene, versus the character-level actions of using your playbook's moves. Bidding for the GM role would have required a separate mechanic, whereas my original system was able to seamlessly merge the mechanics for picking a GM with the mechanics for resolving conflicts within a scene.
Second, I wanted to model the chaos of kitten life. While much emphasis is placed on the partial success mechanics of AW, ultimately characters in an AW-based game are more or less in control of what they're doing, within known parameters of probability. On the other hand, kittens are not in control -- they have limited knowledge and limited control over their own bodies. The card-bidding mechanic of Laser Kittens generates a good deal of chaos. (I had one playtester tell me that she had more fun when she selected her bid entirely at random, rather than trying to purposefully choose a good card.) Moreover, bidding from a fixed set of cards encourages players to deliberately invite failure by spending bad cards, both as a way of refreshing their hand and as a storytelling end in itself. This is something that can't be done with a dice-based system, where each roll is uncontrollable and statistically independent of each other roll.
Third, there are the lasers. I'm planning a longer post about how I developed the laser mechanic, so for the moment I'll suffice it to say that nothing in the standard AW toolkit allows for modeling some of the key characteristics of lasers in the game. Specifically, lasers (unlike character moves in an AW game) 1) build up "pressure" over time until they're forced to go off, and 2) have success/failure levels that can be progressively learned about, and adjusted, during the power-up period.
That being said, translating what Laser Kittens has become into an AW-based system is an interesting challenge, and a potential stretch goal for Kickstarter!
*I know some people regard AW games as super indie. But to me, "traditional" encompasses any game in which there is a distinction between GM and players, and in which each player controls a character whose abilities are defined by a set of "stats and powers."