You need to source the specific Update NSP file (usually labeled [v65536] or [v196608] depending on the scene release) and install it via a tool like DBI or Tinfoil.
The Switch version, developed by , brings the full experience to a handheld format, though with some hardware-specific trade-offs. green hell switch nsp update eshop portable
Green Hell is not a "one-and-done" game. The massive updates add 20+ hours of story and new mechanics. You need to source the specific Update NSP