Though DMC1 is my favorite game in the franchise, it had a ridiculous and broken difficulty curve and other mechanics that didn't work.
I'm going to assume that this statement summarizes most of the replies in this topic, right?
I'll just go on to explain why I like DMC 1 over DMC 3 since DMC 1 was better in terms of difficulty and gameplay. Difficulty, to me, is determined by enemy AI and the limits of gameplay. Gameplay is determined by the mechanics of the game and its control scheme. I just think that DMC 3's mechanics allowed for faster action and it nicely filled out the PS2 controller with its control scheme. Everything else it fell behind. I'll say this as a person who has played a good number of action games.
First off, Enemy AI in DMC 3 was pretty much crap in comparison to DMC 1. The enemies don't have a frequent pattern of attack until at least Very Hard mode. Even then, their attacks are pretty simple and aren't very hard to predict. In fact, a majority of them have only one attack and a simple pattern of executing it. Ultimately, their strength lies in their numbers which doesn't become troublesome until Very Hard mode. DMC 1 pulls this off very nicely because the enemy's AI is the equivalent of the AI of the zombies from Resident Evil. Furthermore, even the most basic enemies have different types of attacks and the only way to effectively predict them is to pay close attention to their movements.
The limits of the gameplay are very rare in DMC 3, which we all have praised since giving the players freedom is always a good thing. However, there's a point where the gameplay has to have a level of difficulty in itself so that there isn't an easy way of mastering it nor an easy way of defeating your opponents. For example, I can just monotonously attack my opponents with just a simple combo and dodge pattern. A boring way of playing the game, yes, but its easy and effortless. DMC 1's limits were apparent but rewarding, you can't switch your weapons on the fly, instead you have to pause the game. This is fine because it gives you time to think. You can't shoot without holding the R1 button, but again that's okay because it is a Resident Evil game and it makes shooting a strategic mechanic (especially since most enemies aren't staggered as much as they are in DMC 3 and alot of enemies can resist sword attacks so shooting is a form of strategy).
In terms of mechanics, DMC 3 is more speed- orientated, so quick execution of any action is a forefront of the action. Which again is a good thing since DMC 1 wasn't all that fast in action execution. However, DMC 1 did have mechanics that boasted an effective challenge to the player and, ultimately, understanding the game was key to making things easier. Though mechanics like Fixed Camera angles were annoying, others such as pausing in order to switch weapons made strategy the primary focus of the game as opposed to style which is what its known for today. DMC 3 also made free- form combat a major focus, but did so at the price of difficulty which gave way for easy methods of fighting. DMC 1, again, was strategy- oriented, so there wasn't an easy way of doing things but there were ways to make things easier such as how slash- cancelling made it easier to execute combos. Speaking of which, one set back I found in DMC 3 was the focus on input- based combos. DMC 1 had time- based combos, so instead of having Combo A, Combo B, and Crazy Combo B, you had Combo A, Combo B, and Combo C which you can switch between depending on where and how long you pause between button presses (some saw this as a set back because enemies can block your attacks after the pause, though I've never had issues with it). If they kept the focus more on time- based combos you can have a total of at least six combos all on one button.
And in terms of control scheme, DMC 3 had a use for every button which is what I like, even though I don't even see the point of the Circle button anymore since I don't use it. DMC 1 had some buttons that weren't used all that often and a few that, if I recall, didn't have any uses. Though I like how it focused on the necessities, I would prefer to use everyone of my fingers.
Now, what I would like for them to do in DmC is to employ DMC 1's focus on strategy as much as it does on free- form combat. Basically, if they are going to give me all those moves to use, I'd better use them all. The enemies better have specific weaknesses and strategies to get to those weaknesses instead of me just pounding on them. And I don't mean they have a weakspot with shields in front of them for me to just walk around (dumb Dullahans) or them just be jumping punching bags (stupid Arachnes). I want to feel as if all but the most basic enemies were bosses. If they do that, I would really enjoy the game.