Played it for a minute, all three friends, both buttons — not the walk, since that isn’t built yet. I sell pixel-art asset packs on itch, so weigh that.
Somi, and for a reason you can use. She’s the only one whose pose breaks her outline: raised paw, satchel strap across the body. I cut all three to flat silhouettes at 64x64 — Bori and Bami overlap each other 67%, while Somi overlaps either one about 40%. Bori and Bami are the same sitting block separated by ear direction and coat value, so they read as palette swaps where Somi reads as a character.
The pat is flat, and it’s measurable. Your rule is translateY(-8px) rotate(-3deg) over 380ms on a 360px sprite — an 8px hop is 2.2% of its height, and it’s the same frame moving. There’s no second pose. You already address the sheet as a 3x2 grid by background-position; one more row of happy faces makes that hop a reaction instead of a nudge.
Unasked: characters-v01.png has no alpha channel, so each cell’s cream square is visible inside the round picker chips.