Im looking forward to the new year when I have some free house time and am going to be setting up my tank for a few days.
The gunge flows into a large pool and it has room to play a few games in before the tank is released!
I was going to get a few pool noddles and place them in the middle of the pool separating the tank from a simple child's game (one of the puzzle games with placing the shapes in the right slots.
To get the pieces you have to slide under the noodles to the tank end where there are several gunge balloons suspended from it In them are the pieces for the puzzle. along with a few just gunge. each time you pop one and get a piece back under and solve the puzzle.
You can do it as part of a race slowest time ends up in the tank to get a full gunge!