If you mean the adventure game Deja Vu it was easy compared to Shadowgate and especially Uninvited in the same series. Deja Vu I completed, but never got far in Uninvited.

Apart from Uninvited the game I had most problems with was an old ZX Spectrum game called Gyron: http://www.mobygames.com/game/zx-spectrum/gyron

I also tried replaying Heavy on the Magic - http://www.mobygames.com/game/heavy-on-the-magick -, a game I actually completed back in the '80s. But 25 years later I could not understand how I managed to beat it.

Games nowadays and generally from about 1990 are easier than those old 80's games.
Or maybe it is I who have changed? After all I never beat Civilization on Emperor level until I replayed it last year.

I can confirm this. :D

Oldest game I played was Hover Force on the Intellivision. As for the hardest, I'd have to say most 8-16bit platformers. That water race level in Earthworm Jim 1 still gives me the chills even though I eventually found out about the hidden oxygen supplier near the end. And, obviously, the previously mentioned Ghosts 'n Ghouls/Goblins, Bionic Commando, Mega Man, Ninja Gaiden and Castlevania titles all deserve their spotlight in the top hardest old games.

Also, since I grew up playing point & click adventure games, I'd have to say most of those were also hard as nails, some puzzles/dialogue options/item combinations were so obscure and illogical that it was downright absurd. I particularly loath the faerie maze sprite puzzle and the "use ratsickle on door frame" tower puzzles in Dragonsphere. And, yes, those puzzles took place even *before* the game itself started, it was just the prologue!

Believe me, it's not easy for us either. ^^; Nowadays, I just go for it. If there's a guy I like, I just go for it and ask him out for coffee. But in my teens? Impossible. I'd rather play a punishing, infuriating video game. That seemed easier in comparison. xD

Amiga people around?

Shadow of the Beast

Now that's hard. Like, impossible to beat?

Playing Zeliard with maps, tsk tsk tsk. That's cheating! >:3

... I kid. Of course you need maps. You talk about the Inferno level, but I couldn't even get to the second boss. xD Strangely enough, it hadn't occurred to me to draw maps. I was ten, though. :)

Maybe I was just really young, but I thought "The Dark Castle" on the classic mac was quite tough.

http://www.youtube.com/watch?v=KCkbp4wurW0

For 80's game it's aged rather well. Makes me wish GOG carried some of these old classic mac games. The gameboy esq black and white graphics look far superior to the cga counterparts of the era on pc. IMHO.

I also remember Phantasy Star 2 (genesis / megadrive) as being really tough - not impossible. just a long tough grind. and confusing as F#@$ dungeons.

Wow, now there is a game I had not thought about for a long time. Enjoyed that growing up.

Oh, never had problems with this game. Maybe because I used a trainer...
<_<

I remember Bushido (DOS) being super hard back in the day.

Simply the hardest game ever made in my opinion. It is not difficult in a reaction-time way but it will totally fry your brain. I lost way too many hours of my teenage years on that game. Should have been out kissing girls. :(

BTW, the game can be downloaded for free here:

http://www.myabandonware.com/game/wizardry-the-return-of-werdna-the-fourth-scenario-k8

The real test today is how long you will play it without cheating.

I actually wonder: were the games of our childhood really *that* hard, or could at least part of the difficulty be explained by the simple fact that we were kids? If we would play those exact same games today, would we find them as punishing?

Concerning "Dark Castle", I don't remember playing it myself, but I've seen an extensive retro review of it, and it looked more like a case of bad game design rather than true difficulty. One would probably die often because of the the clunky controls and unintuitive mechanics of the game. Then again, the retro review in question was for the Mega Drive version, and I believe it's considered a rather poor port, so maybe this doesn't apply to the Mac version.

Contra on NES was hard because of the shitty perspective, clunky controls and selfish life system. Never really bothered to try to finish it (without the cheats) due to the unfair/unreliable gameplay mechanics.

La Mulana on the other hand is hard as nails too but not bcause of crappy mechanics, just because it was designed this way.

Inferno (Sega Genesis) was a fairly brutal game. I had to use a controller with slowmo to make it even remotely approachable.
And I can't repeat the Ghouls N Ghosts series enough. I rarely ever make it past the first level.
Not hard exactly, but Turok used to frustrate the hell out of me, especially Turok 2 because the levels were so big and the draw distance was so poor that getting lost was easy.
And one more Genesis game: The Adventures of Batman and Robin. Think Contra with Batman.

We don't link to abandonware sites here.