/d/games are interactive, /d/games primarily rely on their gameplay systems to generate content. Either literally in the case many games thatll fill out descriptions of sex scenes using your stats, character info and game play a la
Lilliths Throne (LT), or with battle fuck systems, RPG mechanics, Romance mechanics etc etc.
What /d/games are not are visual novels. Generally if a game doesnt keep track of multiple variables evaluating your gameplay performance in any aspect then it isnt /d/.