Honestly, there's a whole bunch so I'll just go with the '17 confirmed games.
Day 1
* Mario + Rabbids (third party developed and published, so I count this one!)
* Golf Story
* Stardew Valley
* Steamworld Dig 2
* Hollow Knight
* Nine Parchments
* Battle Chasers: Nightwar
* Shakedown Hawaii
100% - Probably not day 1
* Escapists II
* Axiom Verge Multiverse
* Monster Boy and the Cursed Kingdom
* Overcooked
* Farming Simulator
* Sine Mora EX
* Rime
* Rocketleague
Likely
* State of Mind
* Thimbleweed Park
* Azure Strike Gunvolt Striker Pack
* Re:Legend
* Yooka Laylee
* Runner 3
* Battle Princess Madelyn
If/when the price is right
* WWE 2K18
* Fifa 18
* The Mummy Demastered
So quite alot.