An amazing Dynasty mode makes this game great.
The other gameplay modes aren't even necessary because all of your time will be spend in Dynasty Mode. You can play exhibition games, College Classics, mascot games (lame), etc. I can assure you that you won't be spending any time in this area of the game.
The commentary for the games becomes very annoying much like any other sports game. I can't tell you how many times I've heard Lee Corso say "When he smells blood, he goes in for the kill!!!!" You're better off muting your TV and listening to music than hearing the same commentary over and over.
One interesting new feature in NCAA '05 is the implementation of home-field advantage. You can take advantage of your home games by "pumping up the crowd" to get an opposing quarterback rattled. This is a key factor in many games especially in critical situations. You can easily force an opposing freshman quarterback into mistakes by getting the crowd into the game.
NCAA '05 is a very nice college football game with a great Dynasty Mode that keeps you playing to improve your team's prestige.