I've only played this game a handful of times in the wild. I too look forward to owning one someday. But, what I like about the game is the code is easy to understand. You don't need to know the ins and outs of it. It's pretty intuitive.
I like the flow and the combo rules and also the rules about hitting each shot 3-4 times that starts a hurry up. When you hit all the main shots the 3-4 times you get a special mb.
Great animations, great monster theme, great sense of humor. Lots of different mb... And the stacking of the mb's actually make sense. I really enjoy when I stack Martian MB with other mb's. As that's a great way for points.
To me the layout and playfield is wide open. But, has really cool toys and just the right art to make the game pop and work. Same with the shaking martian toys.
The big mothership ufo is also one of the coolest toys in all of pinball history.
I know I said I liked the code... But, I really think its a well coded machine. There doesn't seem to be any useless things. The lower inlanes you want to light to get stroke of luck, which can give you cool rewards. And spelling martian is something that I never really focus on... But, I sure do focus on hitting them during an martian attack and as stated you get one heck of a reward.
The only gripe I do have is the music to me. While fitting is only good. Its not great. As stated it fits the game, and so doesn't get old.
It might be too easy for some people... But, I think if you have a multi-pin collection who cares about difficulty.
Oh and it has a video mode that both is fun and fits the game. And it really doesn't take you out of the game long enough to detract from the pin.