Build a maze that earns its space.

1. Start with a turn, then add firepower

Begin in Easy if you want to learn one entrance at a time. Classic adds a second crossing route. Place a short row of inexpensive Pellets so ground creeps must turn around its end, then put a stronger weapon where it can cover the approach and the return journey.

Keep an open route from every entrance to its exit. A placement that seals a route is rejected. The wide gates let creeps enter at different positions, so do not assume every enemy will walk past one tower at the same distance.

Extend your row a little at a time. If creeps already spend a long time in range but survive, buy damage before adding more empty corridor. Click a tower to inspect its range circle and check which lanes it actually covers.

2. Prepare for the first flying wave

Flying creeps first appear at wave 7 and ignore your walls. Watch the upcoming-wave display and reserve gold for air defense before they arrive. Pellet and Squirt can hit air; Swarm specializes in it. Dart, Bash, and Ink cannot hit flying creeps.

Place air defense around the direct flight routes rather than the far end of your ground maze. An expensive tower in the wrong corner can spend the whole wave without a target.

3. Upgrade a useful position

Choose a tower that sees repeated traffic and upgrade it. High-damage hits are especially useful against Dark creeps, whose armor absorbs weak attacks. Use the tower guide to compare costs and final upgrades instead of assuming every level increases range or speed.

A selected tower can upgrade once with U, or queue upgrades toward its maximum with Shift + U. The marked tower upgrades as gold becomes available. Upgrades take time and stop its firing, so stagger them while other weapons cover the lane.

4. Make support towers count

Put Frost beside a section already covered by damage towers. Slower creeps spend longer under fire, but immune enemies need another answer. Place Boost so its footprint touches the side or corner of your strongest weapons. Several Boosts can affect the same tower.

For example, a level-one Boost adds 10% damage to each touching weapon. Two active level-one Boosts add 20% in total. The bonus does not travel through a chain of ordinary towers: each weapon must touch the Boost itself.

5. Plan purchases without counting them as walls

Hold and drag to preview a row. The cost appears before you release. Affordable towers are built, and orders you cannot yet afford remain queued until gold comes in. Queued towers do not shoot or block creeps.

You can cancel an unpaid order without a sale penalty. Review the queue before enabling many automatic upgrades: construction orders reserve priority for their cost. A long shopping list can delay the firepower you need immediately.

Read the creeps, then change the plan

Select an enemy to see its remaining health, recent damage rate, and an estimate of whether your current defense will stop it. Treat that forecast as a planning aid: targets, routes, and tower availability can change during the wave.

When a run falls apart

• Ground creeps leak: check whether the route actually stays in range. Shorten an uncovered detour and strengthen the shared firing area.
• Flying creeps leak: move investment toward their straight flight paths and add air-capable weapons.
• Armored creeps shrug off shots: favor stronger individual hits instead of more low-level towers.
• A wave overwhelms an upgrade: stagger upgrades and leave another weapon active beside the same lane.
• Your plan is hard to read: pause with Space, inspect the towers and queued orders, and turn the grid on or off to suit your view.

Sandbox starts with 10,000 gold for experiments. Try a compact maze and a sprawling maze, then compare which towers spend the most time firing. A current run ends when you leave or refresh the page, so open guides in a separate tab while playing.