These are games that you can only play on Apple Arcade.

All Apple Arcade Games: https://www.backloggd.com/u/tendog/list/all-apple-arcade-games/
Apple Arcade's Graveyard: https://www.backloggd.com/u/tendog/list/apple-arcades-graveyard-former-aa-games-that-you-cant-play-anywhere-anymore/

Previously exclusive, now available elsewhere:
10/22/2019 - Tangle Tower
9/29/2020 - Projection: First Light
7/14/2022 - Spidersaurs, Legends of Kingdom Rush
8/3/2022 - South of the Circle
9/13/2022 - VARIOUS DAYLIFE, Clap Hanz Golf (as Easy Come Easy Golf)
10/27/2022 - The Pinball Wizard
11/1/2022 - wurdweb
11/14/2022 - The Oregon Trail
12/16/2022 - HEROish
1/27/2023 - ATONE: Heart of the Elder Tree
3/7/2023 - Outlanders
6/1/2023 - Transformers: Tactical Arena
6/8/2023 - Bleak Sword (as Bleak Sword DX)
7/26/2023 - Scrappers (as PixelJunk™ Scrappers Deluxe)
11/10/2023 - Air Twister
2/21/2024 - Pocket Card Jockey: Ride On!
4/17/2024 - Stitch.

Leaving soon:
April 2024 - Hogwash

Missing:
NBA 2K24 Arcade Edition
Disney Dreamlight Valley Arcade Edition