The free games are as follows: (note that some of these have been free in the past)
Coloring Book: https://ec.nintendo.com/AU/en/titles/70010000015005
Not Not - A Brain Buster: https://ec.nintendo.com/AU/en/titles/70010000018206
Pocket Mini Golf: https://ec.nintendo.com/AU/en/titles/70010000027664
Mini Trains: https://ec.nintendo.com/AU/en/titles/70010000021092
Jumping Joe and Friends: https://ec.nintendo.com/AU/en/titles/70010000006665
Robonauts: https://ec.nintendo.com/AU/en/titles/70010000000952
Puzzle Book: https://ec.nintendo.com/AU/en/titles/70010000022259
Links courtesy of Jonzay!
Nice one! I actually wanted to get Not Not, as a casual filler party game, so +1 for that!
(Not Not is a freebie mobile game, so don't expect anything fantastic - but it would be pretty solid for short filler couch multiplayer game between other games!)