AN225 is a bit like that with all it's rows of wheels.
How does the AN225 undercarriage cope with the weight on touchdown? Does it land with no pitch? I can see the rear undercarriage collapsing on this mega-jumbo on landing. All the weight will be on the rear wheels.
Apart from that, it looks like a maintenance nightmare. You would need several cherry pickers on every transit just to check the engines and top up the oil. By comparison, the inboard engines on a 747-400 with RB211 engines can be serviced without steps.
One of the reasons the 777 is so efficient is because
maintenance engineers had an input into it's design. If an aircraft is easy to work on, turnaround times are faster and it's inherently safer. Airbus didn't quite grasp this concept with the A380.
I see half the fuel supply is below the height of the engines (not so good when "gravity" feed is required).