Sony has announced its PlayStation Plus monthly lineup of games for September 2025, which includes a Xbox-published title and a hugely popular farming sim.Further solidifying the friendship between Xbox and PlayStation, next month's list is headlined by Psychonauts 2, the platform-adventure from Tim Schafer's Doublefine Studios, which is of course owned by Microsoft. This quirky sequel launched to positive reviews (and no, you don't need to have played the first).Next up is Stardew Valley, the charming life and farming simulation which really doesn't need much introduction. If you don't yet own a copy or three of this beloved indie game, now's your chance to see what all the fuss is about. Just don't expect to do anything else for the next dozen hours, as it gets its hooks into you.Finally this month, there's Viewfinder. A mix of photo mode and first-person puzzle game, this well-received indie first launched in 2023 and boggled all our brains with its perspective-warping levels and extremely smart gameplay.PlayStation Plus Monthly Games September 2025:Psychonauts 2 | PS4Stardew Valley | PS4Viewfinder | PS4, PS5All three games will be available to claim from September 2 onwards. And, as ever, you have just a couple of days left to add August's PlayStation Plus games to your library. Act now to nab Lies of P, Day Z and My Hero One’s Justice 2, before they leave the subscription service on September 1.Tom Phillips is IGN's News Editor. You can reach Tom at tom_phillips@ign.com or find him on Bluesky @tomphillipseg.bsky.social