There are indeed two games – one subtitled Memories of a Quintessential Summer, and the other subtitled Five Memories Spent With You. Both are visual novels with a strong romance elements and feature simulation elements where you organize the girls' routines and then go on dates with them.
I've never read the manga or watched the anime, so hopefully I'll be able to go in blind. The games do feature new art that has been drawn specifically for the game, and according to the store description, you'll be able to "enjoy visuals of the heroines in their swimsuits and wedding dresses, and the various expressions they show during their days on the island."
Excellent, I say. Excellent.
The games will be released individually and as a double pack, and will be available on PlayStation and Nintendo Switch.