Very innocuous, even tongue-in-cheek, but never intimidating, almost verging on almost boring to someone who doesn't listen closely.
So... something like these:
Edit:
Added two more tunes
I've always thought the cut-off is whether it's near the speaker ("here") or near the person being spoken to ("there"). My native language has a three-way distinction (near the speaker ("dito"), near the person spoken to ("diyan"), far from both ("doon")), so it's pretty easy to just collapse it to "here" and "there".
Only for a limited amount of time, kenja time.
Manipulate nearby water (in glasses, but I am only interested in the water) to first be in the form of water vapor, and then turn back to liquid in the politician's pits and nipples and eyes. Making him seem like he's lactating during a very sombre press conference. Making him seem like he's hyper-perspiring during speeches. Making him seem like he's crying during budget deliberations.
I'll make this happen repeatedly, without drawing attention to it unnecessarily. Just a politician who lactates, gushes water out of his pits, and cries.
Worse than the squircle button design?
I am not wanting vast swathes of white space between elements, but if you're giving them background colors so that you indicate where the user can click (and thus interact with the button) at least have some decency to give them some breathing room. Sure, when hovering you can add an effect such that it either changes color, brightness, or gains a glowy border or what have you, but most of the time none of those elements are hovered! You'd be seeing them all crammed together like sardines in a tube!!
Oh, and I got so riled up that I didn't even address that out of place "ExtraCare scan in store" element. Why is it even covering the "Discover" text? Was the foreground some interactive element that just popped up?
Sorry. The more I try to make sense of the UI, the more I think rounded/squircle buttons are the least of the problems there.