I cant remember much but see what you can make out of it.

First ones a puzzle game.
I think you were a blue alien with protuding eyes, like a slug and it was very much like boulder dash or rock ford. With the falling boulders when you make the dirt or material that under the boulder dissapear . Im pretty sure there were enemies. The game had a remade litte spanish bee instrumental playing and some other cool midis.

Second was a adventure.
It was a point and click type of interface like scumm games and maybe used commands to interact with items like maniac mansion, monkey island I & II , etc.
You were a guy with a jacket and you could select locations from an outer view or map.

For the second:

Could be BLADE RUNNER....(but probally not old enough)

Second sounds a bit like Indiana Jones and the Fate of Atlantis.

Is the first one Jumping Jackson?

Yeah blade runner is too new, the second one wasnt indiana jones (not a scumm engine but similair) and the alien on jumping jack is yellow and his eyes dont protude similarly to a slugs, nice guesses though.If it helps, the games were on demo discs that came from magazines in australia (i think one was PC Power Play. I think some of the demos they came with were pickle wars, the dig and teenagent so id say before or up 1995 the games came out. Also, the games may have been for windows.

Man i wish had some demo discs from that time.

Edited/re-written

About that second game, was it about this obnoxious little brat who started in a sleazy hotel room in search of a professor friend? The game I'm thinking of is extremly cartoonish with a large amount of weird/silly humour, also huge verb and menu icons. I haven't got the name right now, but I've got it on a CD, if only I can find it.

Edit: It could be a LA game, in which case you can only get the name :wall:

I dont think ive played the game and cant remember seeing it. I doubt it was cartoony though, maybe im wrong? Ill keep it in mind though

Edit: What do you mean ill only be able to get the name, Esa protection?

The second one could be what is in Germany "Baphomet's Fluch". I don't know the international name. I think it's "Broken Sword". But that didn't have the interface.

I think the second one is one of the Manhunter games. circa 1989 or so.

The first sounds a bit like Bombuzal, judging by the blue alien with protruding eyes... but that's not like BoulderDash at all...