1: The proportions of it. I can practically see a mouse cursor clicking on the door of the house, saying "open door".
2: The figure in panels 1 and 2. That's almost the EXACT pose that characters in the game were in when facing down.
3: The "Holy crap, it isn't a mop, but a living thing!" ...I just did realize this one. There's a scene in Zak where a woman finds a "broom" sleeping in a bed, then realizes it's actually an alien.
This is NOT a bad thing, though. If that's actually your drawing style, let me be the first to say it rocks completely. Zak was my first REAL game addiction, so it holds a lot of good memories.

Edit: You know, I think even the line "*sigh* What a mess!" was in the game somewhere. But maybe not exactly.