All of the original data files are required to do so, however, we conveniently provide an online store where you can get some of the games, including Keen 1, 4, Dreams and Cosmos 1 for your enjoyment.
There are also mods that can be downloaded directly.
Of course you still have the option to use your old original DOS versions of the game.
Commander Genius will look for games in 2 folders:
* ~/config/settings/CommanderGenius/games (default)
* ~/config/non-packaged/data/commandergenius/games