Maglev

Hovering things are nifty! When I was a boy, all the sweet tanks hovered. This is impractical! Ground-effect engines are both 1) hard to power for a multiple-ton war machine's mass and 2) prone to being interfered with by wind! This is sad. I am making a sad face!

Walking things are sometimes nifty. If you think about it, people are pretty neat! Imagine the complexity necessary to carry us smoothly over the ground. Tendons and muscles contract and expand, joints turn, everything works like a clock-work mechanism. (A rather squishy clockwork mechanism.) It is pretty interesting! Tanks are also neat - in concept, not so much in the bit where they kill people. (Tanks: cool. Tanks shooting things: cool. Tanks resulting in the deaths of sentient beings: morally questionable.) So having a tank that walks is hella cool! Still virtually impossible because of the force required to move gigantic metal legs at any sort of pace, but far more impractical things okay for our purposes. Especially if you can give them all sorts of nifty things that real tanks can't have, like racks of machine-guns and homing-rockets and particle beam projectors. This is the principle behind 'mecha'! In practice there are often other odd things going on, like jump-jets and transforming and combining (!), but the basic foundation is sound.

When hovertanks fight mecha, mecha have a tendency to win! This is basically because mecha are absurd, and so have hella more guns than the relatively-realistic hovercraft. Then the hovercraft explode! This is very sad.

In the "Advance Wars" video-game, the evil-bad-guy BLACK HOLE faction was all about hovertanks. They had light hovertanks and medium hovertanks and hovering troop transports and jeeps, but their most powerful unit was a tank on legs. Every other faction stole the designs! (It's okay, the good guys would never use super-powerful walking tanks for evil.) In the games, the tank (called a "Neotank") is pretty much the most expensive and powerful land unit - in an example of "power creep", it supplanted the Medium Tank from the previous game in that position, and was supplanted in turn by the MEGATANK from the next game. You just can't stay on top!

The MEGATANK fills pretty much the full height of the DS screen in the game in which it appears. Still, it's expensive, slow, and hard to supply. (It only has three shots for its main guns, if I recall.) The walking tank, I do believe, remains superior; in games as in life.