Which genres are lacking on handhelds?

This week's topic has already drawn the eloquent attention of some forum newbies, which we love, so if you haven't paid the forum a visit since last week, you're officially on the welcoming committee. But what of the topic we hear you cry…

Casual games, racers and puzzlers get loads of chances to shine on handhelds, but there are genres that seem a bit under-represented, too.

It's hardly surprising that there are so few FPS games on the PSP, given its unforgiving control scheme, but surely there must be a way of nailing the formula on Sony's handheld? The third person Resistance: Retribution looks to have a promising control scheme, could it pave the way for better shooters on the console?

Then there's the DS, which recently hosted the distinctly non-gamey and fantastic Korg DS-10 program. Should there be more of these types of cartridge on the DS and for that matter, could the iPhone not benefit from that sort of thing too?

And what about 2D platformers? Why does the fun have to stop at New Super Mario Bros? Similarly on the PSP, is there really no other company out there able to deliver another hack and slash-em-up that's as good as God of War: Chains of Olympus?

Go on, do some shouting, you never know who might be reading.