Tanks

You drive a tank around a walled field, shooting enemy tanks before they reach the eagle behind you. Brick walls crumble shot by shot; steel walls do not, until your tank has three stars. Each stage sends twenty tanks of four kinds, and later stages send them faster.

Brick, Steel, and What a Shell Can Move

In the game an ordinary shell chips brick and stops dead at steel. Real materials split along much the same line. Brick fails locally: the impact exceeds what a small region can carry, that region breaks, and the rest of the wall stands there unbothered. Steel spreads the same load through a much stiffer structure and shrugs it off. Real armor is designed around exactly this distinction - whether a material absorbs a concentrated blow by deforming, by shattering, or by handing the load somewhere else before anything gives way.

How to play

• Arrows drive, Space fires and P pauses; one of your shells can be in flight at a time, two once you have two stars.
• Shoot through brick to open firing lanes; only the shovel rebuilds a wall, ringing the eagle with steel for a while.
• One hit on the eagle ends the game; your tank comes back while lives last - three, and one more at 20,000 points.
• Flashing enemies carry the power-ups; stars upgrade your tank until its shells cut steel, and losing a life takes the stars with it.

Read more: Materials