When you first play DMC3, it was hard. But once you learn the mechanics, and gameplay, you have already mastered the game. DMC1 on the other hand... is definitely harder because of the controls. In the PlayStation versions, your sword launch, and your ivory/ebony pistols were "activated" by pressing the aim button together with the sword/gun combo. However, they made it better and easier by leaving it on the action itself. Meaning, in DMC3, once you press the shoot button, it shoots. In DMC1, you have to hold the aim button to trigger the pistol shot or shotgun. Which is archaic by today's standards.
DMC1 is indeed a clunky and archaic experience by the standards of today.
But I find
DMC3 to be fifteen billion times more frustrating for one simple reason: it
did not abandon the camera system or clunky controls of the past games. DMC3's enemies are faster, more aggressive, and rely on a far better understanding of the combat system than its prior two games, and yet didn't update the camera or controls to compensate for them. You couldn't even control the camera 99% of the game, which wouldn't be a problem if the developers had made the auto-camera more versatile and workable than the one in past games...but they
didn't. So you control a character that's supposed to be nimble and lightning-quick to match nimble and lightning-quick enemies, but simultaneously keep finding yourself fighting the claustrophobic camera that is placed far too close to the ground and doesn't move nearly fast enough to keep up with the frenzy of action taking place.
This is one of many reasons I find
DMC4 superior, because the technical aspects of the game actually matched the ambition of the combat system. The devs literally changed the camera speed and distance to allow for more aerial-based moves on the MT Framework Engine, and thus made the action far more manageable. You could actually
see what you were doing, and the difficulty came from the ferocity of the enemies and your own mastery of the combat, not the cumbersome process of adjusting to an abysmal camera like
DMC3's. And that's not even getting to how they improved the fluidity of the controls and reduced the God-
awful clunkiness of
DMC3's horrendously-forced weight and delay on certain maneuvers, like dodging or jumping.