Yes and yes.

Well, you guessed the game right! (at least the series)
Although it's not Harvey so I wonder if you played the game?:) Anyway we're deep into spoilers area here, so maybe it's time to stop already :)

I have not played it. It was just the only one I can think of with an imaginary friend. :P

I can't really think of anything at the moment, so someone else is welcome to a turn.

OK, let's try this:

Help, in that space thing, how can I tell what the blue squares, red spheres and all those other colourful shapes stand for?

Hint: The answer to this is easily found in the manual. So it's a game with a manual. One of those good old proper manuals.

How about "Stars!"?

Nope.

So what are these blue squares and red spheres?

The author of the question must have slept during his geometry classes. He should have known that 3D squares are called "cubes" and in the game they give you extra data. The red spheres are actually crosses (in his defence, the game has a pretty low resolution), and give health. Other objects, all of which are colourful geometrical figures, include switches, weapon or armor upgrades, mines (damage) and portals.

That sounds like some cool shooter game.

It's an FPS/RPG/Puzzle hybrid.

Hey that's cyberspace in System Shock, isn't it?

Yes, it is.

Your turn.

Ok here we go:

I fidget a little, straighten the tie, then knock and lie that I was sent by Barbie's boyfriend.

No idea, so I'll ask (and not the usual "gere/is-it-on-gog/indie-or-classic"):

Whom do you lie to?