What aesthetics do those cute Japanese games use?

I wonder what aesthetic do those cute Japanese games use?

(Plus the bubble shooter one was my favorite so far but it was too hard to play)

I wish there was a Hello Kitty one but they never add any more characters such as Pokémon, San-X and Sanrio etc

Maybe flash games aesthetic but since flash got shut down and these games arent actually using flash player idk what it should be called now

What do you think?