The expression "bored to hell" makes sense now
The rest of the game is about killing the same monsters again and again. The same fat zombie. The game needs more monsters. 15-20 hours of game needs at least to multiply by 3 the number of them. And i see a big problem the fact that they appear from nowhere. They teleport constantly.
Developers should concentrate more in fun, and less in graphics. I will not play again this Doom 3. And i can say i played the original version thousands of times.