I guess you could do it, but it's not really just a simple sine wave. If you look at it more closely, different body parts move at different speeds, some get delayed behind, etc. But I think if you draw it to a pixel perfect canvas, it would look okay-ish :)
Oh, I know. Even getting decent results would require different displacement functions for each sprite, because some would squash purely vertically while others have different degrees of horizontal lag to the squash and stretch.
I’m just saying I’m glad I’m too busy to get nerd-sniped from that, because it’d be unfair to you if I did produce something sufficiently okay-ish.
Will do.
For now, I’m focusing on finding time to work on some neglected existing projects, preparing an initial release for a tool to streamline human-assisted OCRing of manga, and considering whether my plans for a tool to prepare tile atlases (as an assist for a platformer I want to code) should broaden into a free and open-source competitor to Pyxel Edit.
(But it definitely is an interesting UI design question… what controls would need to be exposed to an end-user to make it properly useful.)
Juice FX by CodeManu (itch.io)
I haven't dug to much into the tool. But it may offer what you are looking for.