Nintendo have taken to their Topics section on the Japanese website to reveal some small details about 1-2 Switch. Some of the minigames have extra challenges or alternate rewards upon completing them a set number of times or within a certain time limit. Here is a list of the different challenges, rewards and features you can encounter. (Please take into account that this is a direct extract from the Nintendo Japan website so some translations are not exact/correct to the context they concern).

” Shaving ” which shaves beautiful squalry beards on HD vibration .
If you play three times or more in a row, you may be challenged to cut the hai . Let’s cut the head hair with Joy-Con as a clipper. Because shaving and shaving angles are different, you may be able to win against opponents who you can’t easily beat in shaving.
The Joy-Con is a magic wand, turning round, accumulating magical power, bumping magic ” wizard “.
During the battle, you can rotate the Joy-Con around and around to charge up power which you can expel for a more powerful attack. Be careful though as this will leave you ungaurded.
Evidence that magical power is accumulating when such ripples appear on the screen! If you stick on in this state you can push your opponent with a powerful magic attack. However, when accumulating magical power, attention is necessary because there is a gap.
Use the Joy-Con like a telephone handset, the fast take-up confrontation ” Telephone “.
When you play two or more times in a row, you will get other bell sounds on the phone.
You will be able to enjoy a slightly different way of your own sound without being deceived by other bell sounds.
“Treasure Box” Open the treasure box tangled in chains, ” Safe Cracker” compete agains the clock to open the safe .
It is a game in which you compete together against the clock to open the safe and treasure chest. Your Clear time can change the result of how much treasure is contained in the Safe or Treasure Chest. There are 4 types of treasure for both games. You need to clear it as soon as possible to get the best possible treasure. Why don’t you challenge it over and over, try aiming for an even better treasure?
These screens are the maximum treasure you can win in each game. Be sure to check out the tremendous treasure with your own eyes.
Source: Nintendo Japan