Slime Rain

Slime Rain is listed here under Hypercasual. There is no launcher and no install between you and it. It is built for touch, so a phone or a tablet is the natural place for it. Listed under 2d, arcade, avoid, collection, endless.

It is drawn for a tall screen, so it fills a phone held upright rather than a wide monitor. Close the tab and come back later; the game is still one click away.