Pseudoregalia is absolutely my favorite in a 3D game i love that you acquire an upgrading wallkick instead of a double jump and have to learn how to manage your wallkicks like theyre a consumable resource, and each one even has a slightly different S/FX to keep you aware of how many “uses” you have before landing, and your jumping & climbing moveset is built around them while never superceding them. its closest 2D counterpart is your dash + wallcling from Celeste which i will name as an honorable mention even though i agree with Artee that a wall cling is a subtly but importantly different mechanic. co-signing everything Wizball said as well
Super Mario 64 is my runner-up for 3D wall jumps. they’re perfectly tricky-yet-doable enough to be satisfying, and at almost the perfect ratio of useful:mandatory – i kinda wish you had to apply them once or twice more, but the whole structure of SM64 means that stars where you need it are skippable anyway. also “Wall Kicks Will Work” is my 2nd most memorable star goal name after “Metal-Head Mario Can Move!” and i love that in the world of Super Mario 64 those are statements of equal value
For 2D it’s got to be Super Metroid i will forever love that it is a completely optional skill that, like SM64’s is both tricky but eminently doable and even having a remedial knowledge in it adds texture to every single playthrough (e.g. maybe you don’t have the patience to wall-jump and ball-bounce all the way out of Norfair on first visit, but you can definitely get good enough to shortcut some powerups and generally make controlling Samus feel more fluid)
And god, Dechoras and the Etecoons my favorite ‘80s post-punk band the fact that two of your major optional, unspoken skills are taught to you by cute lil alien guys completely through animation. who you also have an optional chance to rescue in the endgame if you just feel like being a nice super player. i love Super Metroid so fucking much dude