Here's one which I particularly would love to see.
Make a hack of Super Mario 64 DS which maps the analog controls that are used for the touch screen, so that you can use said analog controls with the analog stick on a 3DS or any emulator, effectively revamping the whole gameplay to SM64 levels of smooth playability.
i play this one on my GPD XD+ with analog movement, but it is glitchy AF to get to work, and it only works with the built-in left stick (no controllers do it)
and i have to use a mod Skellux made that you patch to a SM64DS rom (it makes the cursor on the bottom screen not move around at all, after it appears. this is MUCH better on it's own, and functions similarly to the "analog stick" on the lower screen in Rayman DS)
and then i use the floaty button things to make the left analog stick move the touch cursor on the device to the (simulated) DS touch screen.
basically it's like mapping the analog to the touch screen of the device, and make sure the touch screen of the DS lines up with it.
it's not an easy setting to get to work, and if i open other DS games it throws off all the settings again.
so basically i got it working and figured out. the side flip move (one of my faves in 64, and almost impossible to even do on the DS) i can do them one right after the other (just like on the N64 version)
maybe all DS games could use hacks or "emulator settings" to get them to work right.
i mapped the Dementium controls to work with both analog sticks (AWESOME) and you can still use the touch screen for puzzles, it is just a real butt-pain to have to change all the settings every time, and i couldnt get the Fire (trigger) to work while the right stick "mimicked" the touch screen,
(the N64 emulator is the only one i know of that lets you map different settings for every game, and i know about "front ends" or whatever i've just never played around with them.
but this could be useful for a lot more DS games too. any game that needs analog movement (left stick) or analog "look" (right stick, for FPS games) could get little control patches that get them working better.
but SM64DS is a game that should have never had a "run" button to begin with. it's implementation is SUPER shoddy as well. the game needed a button (preferably the "L" button) to be the "slow" button.
here are my ideal controls for SM64DS (these could be applied so these controls work on real hardware, AND for things with analog sticks, like my GPD XD+ or any tablet)
D-pad - movement, always full speed (hold "L" to do the tippy toe slow walk)
R - crouch/SAME
Y - Punch
B - Jump
(so these 2 mimick the B and A on a 64 controller)
X - camera Left
A - camera right
(so these mimick the C-Left and C-Right buttons)
start/select - same
the camera zoom in/out could still be in the right lower corner of the touch screen (but i would prefer it be added to the select button (too), so wouldnt have to have ANY touch screen controls)
this would be the best version of the game. best way to play on a DS and 3DS especially.
i think it was Nintendo's policy to try to add tacked on crap to games (wacky new touch and waggle stuff) so that may be why they didnt give us an "always run" option. that would have helped at least.