Here you can find Doom, Hexen and Heretic games all together. It's a very good offer for a classic FPS gamer especially need a flashback to 90s. There's only one missing in all three games: Musics! They have been removed to avoid a huge file size.
You can select one of them from the main menu. Gameplay and controls are almost the same with the originals and you can change them, customize keys from the game menus.