A lot of people have mentioned It takes Two, which really is great and you get to try many different mechanics.
You can also check out Fling or Keywe on steam. Only 2 players max (as compared to 4 players on Overcooked or Plate Up), but less complicated controls. Bread & Fred is another I've been meaning to check out too.
Unrailed has simple controls but more objectives to accomplish, and Out Of Space is similar to Overcooked but not in a cooking setting.
Edit: Didn't realise I used a shortened name. Fling refers to 'Fling to the Finish'
I have to say that this highly depends on the type of games you like, and if the unlocks are well designed into the story.
In general most of the types mentioned are cashgrabs, but I enjoyed an indie game called Evoland. You can 'unlock' better graphics and audio as part of the game, watching the evolution of gaming