Seems like Captain Toad for Switch is free for a week (5 Aug to 12 Aug), provided that you have access to a Japanese account to download the game, plus have an active Nintendo Switch Online subscription. I would likely take advantage of this privilege by basically rushing through the game, since I am yet to play the new Odyssey-based levels. Unfortunately I don't have a Wedding Mario/Peach/Bowser amiibo so I can't unlock those levels immediately.
I don't think the DLC levels are available, which is a shame.
Thank you for reading.
P.S.: I have already created a Marioverse thread about this.
Thank you for reading.