in my obsession with building control panels having minimal inputs, I started putting together this list:
bubble bobble
snow bros
ghostlop
pang (series?)
puchi carat
cameltry
ghox
pop n' pop
and then there were a few that came close:
diet go go (uses down)
puzzle bobble (uses down)
puzzle de pon (uses down?)
magical drop (needs down)
money idol exchanger (needs down)
dr. mario (uses down but not up - excluding the menus)
probably many Tetris variants don't use up, right? bloxeed, puzzled, joyjoy kid.
any others?
edit: oh, platformers. does smb1 NES use UP at all?
What about games where up and down do things, but aren‘t really necessary? In the 2D Sonics you press down to perform a spin dash (or to turn into a ball), but I don’t think you ever NEED to do a spin dash? I just played through the first two acts of Sonic 2 without pressing down as a test, and I didn't really feel like I was restricting myself in anyway.
(Pressing up make Sonic look up, but again, this isn't at all necessary.)
Edit: ok, Chemical Plant Zone is a little trickier, and certain routes might be a little weird since you can't become a ball unless you jump, but it's still not that hard to get through without pressing down
this is a tough category. I noted above a game called Diet Go Go which doesn't use up and only uses down to drop down through platforms. Do you NEED this functionality to play the game? Sorta, maybe. I'd prefer to make separate lists, focusing primarily on entries that have no utility for U/D (except maaaaybe menus…).
Because I think it'd be neat to have an arcade stick that only had L + R! Apparently there are 'gates' available for this, just like square and octo. Or you could go the hitbox route and just have 2 buttons for L/R instead of a stick. And even L/R/D for magical drop, make L and R similarly sized and make D a differently sized 'special' button to denote it's unique function and deferring(?) to how infrequently it should be pressed relative to L/R.
It's similar to when I was making lists of MAME games which use limited buttons… there are some 3-button games that you COULD play with only 2, like a beat-em-up with no super moves, but it doesn't feel 'clean' to me.
[On page 3 of the US manual for SMB1](https://www.gamesdatabase.org/Media/SYSTEM/Nintendo_NES/manual/Formated/Super_Mario_Bros._-_1985_-_Nintendo.pdf), the functionality for the Up arrow is listed as "???". This drove me **insane** as a kid thinking that it was some kind of secret functionality. Unfortunately, I just think it's bad technical writing.