I’ve been looking through various collector sites searching for Millennium Falcon items that i haven’t yet discovered and came across the “Wonder World” by Hasbro.
Dated 1995, it’s part of the Power of the Force range and looks pretty interesting. (I’d be interested to see how much like Micro Machines the spacecarf are.)
From what i can see, you fill the tank up with water and a special powder turns the water into a gel. You can then float various ships, laser beams and asteroids to make your own space battles. 🙂
I can’t see this having much longevity as far as play value, but it’s an interesting item. You can pick them up pretty cheaply on ebay, but shipping to the UK can be prohibitive.
Mffanrodders's Blog 
I have one of these and to be honest there’s nothing in the set to get excited about except for the Falcon itself. You might think about asking the seller to open the box and send you the Falcon alone — it would be a lot cheaper to ship.
The vehicles are made not of plastic but a hard rubber. I know that time can be cruel to rubber and they do get literally impossible to dust — I keep mine under a clear plastic dome salvaged from some toy packaging so I can display it without worrying about dust sticking to the surface.
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