If you're looking for similar gaming experiences on the PSP, here are some top alternatives:
Since Uncharted 4 cannot run natively on a PSP, here are your best legitimate options for gaming on the go: 1. Uncharted: Golden Abyss (PS Vita) The only true "portable" Uncharted game. Features full touch and motion controls. Developed specifically for the PSP's successor, the PlayStation Vita 2. Steam Deck / ROG Ally / Legion Go Uncharted: Legacy of Thieves Collection is available on Steam.
To be clear right away: