Starting room, with your tank. The green energy bar shows your status.
Next room, below the starting room. Nobody here but me. The energy bar is greyed out until you start moving.
Another empty room. Many more to come. I guess the GB-symbol is General Budda's banner.
Ah here's something else but walls... an exploding orb. If you touch them they just disappear, no visual effects other than a reduced energy bar.
Aha, a keyhole, but I don't have a key yet. Note that the orb to the left is half-drawn, this is an effect of the drawing routine, as once you start moving the sprites flash a lot.