It was not obvious to me whether the Steam Deck is a separate game system or not, as it is basically a handheld PC running a Linux variant.
Reasons for the Steam Deck being its own system:
1 Screen Platformer
Steam Deck 2022@3325
1993 Space Machine
Steam Deck 2022@3324
ocdgamer.rb:337:output_game_list( 10 games, mode:largescreen, tag id:81, sortby:title, url_arg_prefix:, output_list_selection:true) output_large_game_box(3325) output_large_game_box(3324) output_large_game_box(3314) ... execution time: output_game_list: 0.00s