I think that Crash Bandicoot: The Wrath of Cortex, still has the same design as Cortex Strikes Back and Warped. The are still exactly five warp rooms and still six levels in each.
Sound is good, especially the avalance and tsunami. The music fits in perfectly with the setting; e.g 'Bansai Bonsai' has oriental style music and 'The Gauntlet' contains medieval themed music. I think Crash makes less noise in Wrath of Cortex, than in all others. He doesn't make any 'WOAW!' when he gets beaten by a creature or robot, and when he gets three Uka Ukas, there is hardly any noise! (I didn't realise I had three, at some point!).
Graphics have improved a lot; heat from fire makes the air appear to move, and water looks more realistic. The crates look more wooden (not cardboard), and the wumpa fruits have more fine detail. On the other hand, certain figures and models haven't improved all that much.
The gameplay itself is the same. They could try something a bit diferent, however I don't mind this. Loding takes some time on the PS2, but I wouldn't say enough to really bother you. (Sometimes it's worth the wait). There is no storyline whatsoever, and it's just Cortex trying to take over the world! Four times in a row! I do like the idea of the four (or five) Earth elements, and their respective bosses, though. The ability to play as Coco (Crash's half-sister) is good, because in Warped, she didn't have her own set of moves.
The extra features are the same as well; their are still relics to collect in time trials, and gems to collect too.
Overall, I like and enjoy Crash Bandicoot: The Wrath of Cortex, but a change in gameplay wouldn't spoil the broth.