Right across the street from the cup noodles museum is a little amusement park with some rides.
An easy/fun way to access that area (Minatomirai) is to take the Sea Bass boat from Yokohama station.
Nearby that area is Orbi in the Mark Is building, which is a 3D nature theater experience thing. I haven't been, but it may be fun.
In the area of strangeness, there's always the Tokyo Sewerage Museum... A hands on experience for kids.