DOS Games can be among the most difficult video games to get running. Even if you get the game running, you still have to consider things like getting the sound working or calibrating the joystick.
A DOS Game is about the whole experience, from procuring a game to reading the documentation, installing the game, configurating the OS and software as need be, and finally running it.
The first point is that any DOS game originally came on floppy disks or on CDs. They generally came in a box with at least an instruction manual and a reference card. The instruction manual told you how to play the game, the reference card how to install the game. Somewhere inside the package would be the means to pass the copy protection question(s) the game would ask, if any. If the game had disk-based copy protection, the original disk(s) would be required to play the game.
I dislike the modern way of packaging DOS Games, namely as directories after a full install. There are games that only install certain options from the floppies. Other games have lesser-used options that tend to get left out of the configuration options. By only giving the resulting install, the options are limited to whatever the distributor thinks the gamer should play. Giving disk images is the best way to ensure that a game can be installed properly on any system, real or emulated.
Second, in order to play a game, you have to have a basic understanding of how the operating system works.