Build a tower tall enough to reach the green target height line, then survive a wind test followed by an earthquake. The taller you go past the target, the more bonus points you earn.

Stay in BUILD mode. Tap any yellow ground anchor or blue junction to start a beam, then tap a grid point to place the other end. Every beam auto-creates a new junction at both ends that you can keep connecting to. Set max beam length with the slider — shorter beams cost less. Right-click or tap DELETE to remove beams.

STEEL $3/unit — strong in tension, bends before breaking, medium weight.

WOOD $1/unit — cheap and light, good for low-load bracing, snaps under heavy weight.

R. CONCRETE $6/unit — most expensive, heaviest, best compression strength. Resists sway dramatically. Cracks suddenly when it fails.

Every junction is a free hinge unless braced. Two beams at a joint will fold under load. You need at least three beams meeting at a point — a diagonal cross-brace — for the joint to hold its shape. Triangulation is the key principle of the whole game.

Hit TEST to run both phases back to back. Phase 1 applies wind — taller nodes sway more. Phase 2 shakes an earthquake side to side. Survive both and you pass the level. Beams glow red under stress and show a visible kink or crack when they fail so you can see exactly what gave way.

Each level gives you a budget. Unspent money carries forward to the next level, so building efficiently early gives you more to work with later when you need concrete and steel up high. Score is based on height above target plus budget saved.

Scroll up/down in BUILD mode to pan the view as your tower grows. Switch to PAN / ZOOM mode to drag the canvas freely or use pinch-to-zoom on touch. Ctrl+scroll zooms in either mode. The ⊡ button fits your whole structure in view.