Nintendo is ending 2020 and kicking off the new year with something special for Switch Online members. Starting Dec. 30th, 2020 and running to Jan. 5th, 2021, Switch Online members will be able to play Crash Team Racing: Nitro-Fueled in its entirety. This includes the online component as well!
Once Jan. 5th, 2021 comes and goes, access tot he game will be removed. There's usually a sale for the game during these trial events as well, so be on the lookout for that.
As of right now, this deal is just announced for North America. Hopefully it'll expand to other regions soon.