If you want to think
Parking Escape and Lumen Shift are readable with the sound off. You can pause, look at the board, and come back.
Blockpang and Jelly Pang 2048 use rules that take one round to learn, then the fun is nudging the score up.
Bubbly Lab sorts potion colors into bottles. A stage is 60 seconds, so it breaks cleanly between other things.
If you want speed
Slime Volley starts a match from a few keys. School Zombie Defense and Shadow Survival still fit a short sitting: you grow, then you deal with the next wave.
Check the keyboard and touch notes on each game before you commit.
Pick for the device in your hand
On a phone, large touch targets and a portrait board are easier. On a desktop, arrow keys or a mouse feel more precise. The portal lists the genre and the controls before you open a game.