While the full game isn't available, the PSP homebrew community has created sandbox experiences that capture that GMod energy:
The primary reason Garry's Mod was never officially ported to the PSP is the Source Engine's technical requirements Hardware Gap gmod psp
However, for preservationists and homebrew enthusiasts, it's a brilliant testament to what dedicated hobbyists can create. If you love tinkering with hardware and enjoy seeing how far a portable console can be pushed, booting up QMOD on a modded PSP is a fun, nostalgic trip back to a more adventurous era of gaming. For everyone else, a Steam Deck or a modern gaming PC is the way to go. While the full game isn't available, the PSP