https://wccftech.com/japanese-playstation-plus-ps1-ntsc/

The PlayStation 1 classic games released in Japan as part of the new PlayStation Plus are the NTSC version, and thus run much better than the PAL versions that have been released for the service in other Asian territories.

As reported on Twitter by @the_marmolade, the version of Ape Escape that is available in Japan is the NTSC, which runs at 60hz, as opposed to the 50hz of the PAL version released in other Asian territories.