GTA V was originally developed for the PS3 and Xbox 360. It was later remastered for the PS4 and Xbox One and ported to the PC. While there is no portable version of the game out right now, the recently revealed GPD Win 2 portable system has made it possible to play GTA V on it.
GPD Win 2 is the the latest iteration of the popular pocket sized gaming PC. It supports both keyboard and a traditional gaming controller as input method. While GTA V requires a rather demanding CPU for the game to work properly, it appears to play just fine on the lowest setting running on GPD Win 2.
A video was uploaded on the Chinese website bilibili which shows GTA V running on the GPD Win 2 portable system. The video can be seen from here and judging from what it shows, the game is playable but with barely any impressive visuals. That said, the fact that it can even run on the system is an accomplishment in itself.
SOC Intel: M3-7Y30
RAM: 8GB LPDDR3 @ 1866MHz
Storage: 128GB M.2 2242 SSD card SATA 3.0. Card is user replaceable
Screen: 6″ Sharp 1280x720p capactive touch screen with Gorilla Glass 4
OS: Windows 10 home 64 bit
Here are the general specs for GPD Win 2, which hasn’t been released officially yet, but it is expected to be made available in April 2018.