As far as the idea that horror games on a handheld wouldn't do well goes, we have to keep in mind- some people are VERY STUPID. We can't judge things based on that fact that most of us would be turned off by it, there's got to be more than enough idiot parents buying for their kids or kids just turned into the whole gaming scene that the sheer novelty of a "Scary Game!" would be just too much to pass up- if atleast for the bragging rights to say "I have that game and you know how they say it's scary? It's not that scary!"
Also, it's not too farfetched to imagine starting a new fighting series (or at least a new sequal to an established series) specifically on a handheld- we've all seen the tons and tons of "non-gamer" types whisking out their GBAs at the oddest times, even if only too seem cool by doing so. Just like with the horror games idea, the novelty alone is enough to bring in a market of those desperate to prove their ability of being able to have a "crazy new game" way before anyone else they know- especially from "that company that made that Street Fighter game!" (as witnessed among kids not that well-versed in the gaming community)..
Remember, novelty is a huge selling point. Think about all those versions of the same old football game, or movie rip off- people buy them for the NOVELTY of playing [insert favorite football team] as if they were actually on the team, or the NOVELTY of being able to pretend they were James Bond in a way that wouldn't make their friends get freaked. If it turns out that novelty lust is transferrable to handhelds (and if it isn't, that would definitely be a first for novelty whores!), there is a whole fortune to be made on crap games and stupid gimmicks.