I only play easy games - they're the only ones I can figure out (oldster here - no atari, gameboy, etc. experience

) and some of them, like the faerie cloud racers, just move too fast for my eyes to be able to process and deal with - have a disability.
I start in Action:
Carniva of Terror - try to get the umbrellas, hands and feet - they score higher, and get all the pies you can before they hit the screen - those decrease health. Look for the white boxes with the green cross for health, the wooden chests for more ammo and the red clocks for more time - all three things come down on parachutes
Igloo Garage Sale Game - can be a bore, can be frustrating. But you can do ok at it if you practice
Meerca Chase - I play the old version on easy (I cannot handle anything faster!) - the new one with those moving arms and legs I just can't deal with, too distracting for me. Not great at it, but around 400 np per game
Usuki Frenzy - same 10 items every time and same 10 unwanted items every time. Just get used to which ones you're supposed to pick up. Start in the bedroom, go to the bath (to the right), then into the dining room, then the kitchen and finally the living room. Seems the fastest for me.
Ultimate Bullseye - practice! is all I can say
Faerie Bubbles - another can be frustrating game depending on the combinations. You can get pretty good at this pretty quickly though.
Ice Cream Factory - loooooong game, but if you get 4000 points, you get 1k np per game! Look for the hearts (extra lives), the gun (slows the ice cream coming at you down) and the mini chia (will shrink you chia - good thing) during the ice cream cones coming at you part of the game.
Then Puzzles
Destructomatch - I play on extreme, whichever gets you more np
Spell or Starve - fun, good way to keep your mind sharp
Kiko Match - I always make it past level 11 - that's 1k per play
Sutek's Tomb - another looong game, and the np isn't as easy to get - you need to score 5000 to get 1k per game, but play that on hard and make the screen larger so you can see the blocks
So all together that could be around 20k a day - and I'm awful at games! And doesn't include the gambling games, and others you may be good at.