We've been working on upgrading A Week of Garfield (Famicom/NES) with new graphics, and some other changes.
I've overhauled the title screen (and made other changes) but that's not released yet. (Four-legged Garfield has a little more animation.)
This has a reputation as a bad game, but it at least looks better now.
Our question is about the jump kick. Garfield has a kick attack, and can also kick when jumping, but no animation plays for the jump kick. We've been hoping to add an animation to this for awhile. We still have about three extra tiles which would be enough to animate with, or otherwise the standing kick's art could be used.
For no reason, the jumping, stretching and damage sprites are flopped in the ROM compared to the walking sprites. This has become relevant when messing with the code.
We can experiment with affecting the kick animation by changing ROM address 01D0EB from 09 to 00, and additionally changing 1D0F0 69 to A9.
EDIT: According to Rani, Game Genie codes SXSIIESU+ZESITALP+OKSSAEPX+IESSPALA+PESSZAES+ENSSZAEI+PVSSGESU+YESSIAZE+XVSSTALE+XVSSYEAO+OXVIAEPV rewrite the code enough to get us the standing kick in mid air.
More ideally we would load a construction at 3840 or some other empty space in the ROM, where we could insert new left and right jump kick sprite construction.
Otherwise it could load the standing kick sprite construction.
That would take a different sort of code rewrite than the one I did. We would have to plot out what all the animation frame call numbers mean and possibly shift a few around. Watch RAM addresses 004F and 0342 to see what I mean.
Version with jump kick has now been uploaded:https://www.romhacking.net/hacks/6728/