Finally, someone mentions Ninja Gaiden.

I think the main reasons that games seem to be easier now is that we're older, more experienced, and more skilled than we were when we first started playing games. Another reason some games seemed too hard (back then and right now) is because of just plain bad game mechanics.

Ninja Gaiden was incredibly difficult. The first boss in that game is harder than final bosses in most other action games, and it's a very simple battle in essense. You have a sword, he has nunchuks, just hit each other till one of you dies. No other gimmicks like some enormous monster about to take destroy the world, or some crazy magic wielding villain. Just a guy who is really good at using nunchuks.

The challenge comes when you realize that you can't just attack him blindly. He will block most of the things you just throw at him, and will punish you painfully for it. You have to dodge, run on walls or whatever you can to avoid his attacks, then use your skills to strike at the right time. It's a game of pattern recognition and skill, and you won't be able to progress far if you suck. The game is rated M for mature, so they expect you to be '17+' when you play it, which should be old enough to have fairly good digital dexterity honed from years of gaming.

Ultimate Ghosts and Goblins is another very difficult game, but it does have some bad (or maybe intentionally cruel) design decisions. When you get hit, you get launched backwards. Sometimes, especially on your first few playthroughs, it's impossible to evade some of the stuff that just comes up out of nowhere. Now, there are certain areas where Arthur is on a fairly small platform, suspended over a vat of lava or acid or some other instant-death pit. If you get hit by some random thing that pops up, you get launched backwards, off the platform, and into the pit of burny death. Maybe it really is intentional instead of flawed design, but it sure as hell is frustrating.

Most games now make the controls easier or more intuitive as someone mentioned. This could potentially make some parts of games more bearable. Example: If double jump were to work in Ultimate Ghouls and Ghosts in the knockback situation, one could at least save themselves from burny death if they reacted fast enough. Difficulty needs to come from the A.I. now, not from limitations and flaws in the game system.