They got progressively easier with each edition. In terms of difficulty they're almost designed to be played in reverse! I couldn't finish 1 when I played it in the 90s, and I still can't finish it now. 1 also had that Tomb Raider/Resident Evil style mechanic of not allowing you to save when you want.
The controls are generally spot on with the remakes, though there are sections that handle absolutely nothing like they originally did and are all the worse for it (such as the jet ski on Crash 3).