Now I see why people like it. :) The enemy is just brilliant, and are much more dangerous as compare to the other enemies in the series. First time I die I got killed by a puppet's shotgun. :( Compare the puppet to DMC3's demon and DMC4's scarecrow... ... lol Shadow is also very strong! But so few encounter in normal play through. Blades and Nobody.. ... lol they fall under grenade roll. And frost surely is much more aggressive compare to DMC4. But I don't see why phantom is hard though, only got hit once in the first time. Second time air raid murder it! Too bad there is technically only two weapons, Ifrit and Alastor(The Alastor scene... woah). First time and second time fighting Nelo: Well I heard people saying he is hard... (Defeat him both in first try) Third battle: OMG, Nelo totally murder me... A much harder Phantom Sword Formation lol. Mundus did not kill me as much as Nelo does, I think I die 10 times in the battle. And, is the final Mundus supposed to be like that? He is so easy!!
The Frosts in DMC1 are far easier than they are in 4. Mostly because in DMC1 they don't have super armor so you can actually combo juggle them into oblivion. And they tend to attack from greater distances which gives you more time to react. They also jump around a lot less than in 4.
I'm not saying they're better in 4 by the way. Just more difficult, they're more annoying and less fun in 4 as well.