All you're doing is spreading the energy used over a (much) longer time. That said, the energy needed to lift & lower it is avoided :/ but that' separate. You still use the same energy to MOVE it. In the case of the Hippo, there's 120 pounds of added weight too.

If you go to extremes of course it seems 'off'. But put a single gallon of water in the Hippo and tell me it's easier to roll 130 pounds than carry 12 pounds (10 + 2 pound container) ok?

Or tell me how the laws of physics changed?

The wheel does take advantage of friction to save energy. In space you need to spend as much energy to slow/stop something as to accelerate it. But friction & stuff does that for you on Earth, so there's savings there. You can use momentum to "roll along" at a savings, but eventually must replace the energy lost to friction to keep rolling.