Project T.C.M.P. is a mod for Doom 2: Hell on Earth that specifies the author's showcase of level designing. Like most mods for the game, there will be various monsters, map ideas and other entities to get good recognition in the near future development. And yes, it is mainly suitable for those who are die-hard Doom players, veterans, mapping enthusiasts and probably first-time players (but for children [under 12 years], it's not really recommended - unless either your parents acceptably permitted told to do so, or playing this game with no consent at your own risk). It is more likely to be much challenging and fun, as like other wads released each months and years, hence, playing on "War Champion" aka Ultra-Violence, is highly recommended for you, but it's up to you on your embarked decision to play.
Aside from that, there's a side-story about a Filipino-Japanese soldier, who was assigned as a night guard straight up to 7 hours of work. Yet, the brink of a staged surprise came into the action. Hence, a swarm of unknown creatures from the deep Underworld appears on sight, and they are finding all seen victims to be slaughtered infinitely and indefinitely, including YOU.
Time is running out, so as you - the player, shall start the horrific adventure.
Good luck and let's give a Hell of the ride!