You know what, i've been waiting for a thread like this...
Sound is so important in my opinion! It really helps when say your fighting a hard boss and some heavy cool rock music puts you in the mood no matter how many times you lose and have to try again.
Same goes again for my map, i'm trying to make a song that suits the need and theme.
Man DOOM 3 scares me mostly because of the sounds, Silent Hill 1 again had such damn scary music, it made me think of negative things, like what is going to be around this corner and I wonder why my radio is going crazy.
Then again sound is useful for adding atmosphere, Quake 4 has a lot of explosions and combined with a big bass system really makes it realistic.
Half Life 1 had a few soundtracks and I think it was best that they spread them out, you can have games with music all the time aka ZOE 2 or you can have triggered songs when you fight a boss or are playing a training level.
I actually target my attention towards sound, I make sure my maps have the best sounds to suit it, I consider myself a Sound Engineer because I make good decisions where music / sounds should go - for example: -
Say you had a game with a training level, I would use sound to the advantage here and make it so there are many training choices like walk, shoot etc, now first off calm music would play when selecting what training mission you'd play and then a slightly heavier re-mix would suit it when you actually trying the training subject out...
To sum up - Calm music at menu
- Slightly louder, faster version of the previous song when actually playing.
So yes, music really helps, War games are good with American sort of army music. Scary games are even more frightening with scary music, Tetris is nothing without sound
So I conclude with: Sound is important, imagine playing a game without a bit of music, would you find it interesting, what if you just killed a load of enemies with a cool trap, a sound helps to make it sound cool, no music to add celebration? A game without music should be burned!
Don't overdo music mind.