Your first defense, step by step
- Start as a guest
Enter a commander name on the first screen and select Start Game. Play free in your browser with no installation.
- Summon and place towers
Spend Gold to summon towers and place them on open tiles beside the path. Defeated enemies give you Gold for more towers.
- Merge towers at the same level
Drag one tower onto another. Bow Lv.1 + Bow Lv.1 → Bow Lv.2. Bow Lv.1 + Laser Lv.1 → Rail Arrow Lv.1. The same type gains one level; a combo of different base types keeps the ingredient level.
- Keep growing with an account
Sign in with GitHub or Kakao to save your base and unlock idle production, the Workshop and invasions.
Your first merges and beginner combinations
Drag towers of the same level to merge
Same type: +1 level. Different base types: a combo at the same level.
Bow Lv.1 + Bow Lv.1
→ Bow Lv.2
Bow Lv.1 + Laser Lv.1
→ Rail Arrow Lv.1
Different levels cannot merge. Ingredient order does not change the result.
Beginner combos to try
Try piercing shots along a straight stretch when fast enemies slip through.
Try splash damage at a crowded corner. Add a separate Ice tower to slow enemies and give your damage towers more time.
Start with Bow for basic coverage. Choose a combo for the enemies you face and keep other tiles defended while merging.
Find more options in the complete tower combination table.
Mouse and touch controls
- Place, move and merge: Place summoned towers on open tiles. Drag placed towers to move or merge them. The same actions work with touch on mobile.
- Tower details: Click or tap a tower to inspect its stats, available merge candidates, targeting priority and combat record.
- Sell: Drag a tower to the trash area to sell it.
- Camera: On desktop, right-drag to rotate and scroll to zoom. On mobile, enable camera controls in the View menu, then rotate with one finger or pinch with two fingers to zoom.
- Speed and graphics: Use the pause and speed buttons. Choose a quality level suited to your device in the Graphics menu.
What are Gold and Coin for?
| Currency | Earned from | Used for |
|---|---|---|
| Gold | Enemy kills and cleared waves | Summoning, upgrading and awakening towers, and field devices in the current run |
| Coin | Idle production, invasion bonuses and defense rewards on a signed-in account | Permanent Workshop upgrades and invasions with a Coin entry cost |
A new game resets run Gold. Your account Coin and Workshop upgrades remain. Paid invasions mentioned below use the in-game currency Coin.
Build and defend
Spend Gold to place towers on open cells. Enemies give Gold when defeated, and leaking enemies reduce your lives.
Merge towers
Drag one tower onto another of the same level. The same type gains one level: Bow Lv.1 + Bow Lv.1 → Bow Lv.2.
Different base types form a combo at the ingredient level: Bow Lv.1 + Laser Lv.1 → Rail Arrow Lv.1. Towers at different levels cannot merge.
Different base tower pairs form unique combo towers. Sniper can combine with Bow, Laser, Bomb, Ice, Tornado, or Dark Star for six specialized long-range roles.
Only a pure Sniper gets the 50% damage bonus at 260+ range. Sniper combos trade that bonus for piercing, hitscan, splash, control, or shield-breaking utility.
Click a placed tower to see its stats and ready merge candidates before dragging.
When the map is full, summon, upgrade, and merge materials in the two-slot Merge Workbench. Merging with a field tower keeps the result in its existing cell. Waiting towers do not attack, and battle pauses while using the workbench. Use the help button for instructions.
Idle mode and Coin
From Wave 3, build at least one tower and press Idle/Queue. After the current wave is cleared, the run turns into a base that produces Coin while you are away.
Idle Coin scales with cleared wave, tower power, and unlocked combo count. Stronger towers matter more than raw tower count, and rewards stop at the storage cap.
Workshop upgrades
Use Coin in the Workshop to unlock permanent upgrades: more starting Gold, cheaper towers, stronger damage/range, better idle output, and a longer idle cap.
Satellite Charge Research is a one-time 5,000 Coin purchase. Right-click or touch and hold Orbital Strike to toggle auto fire. While enabled, a ready charge fires automatically when the leading boss passes one-half of the entire path. The interval is 2 game seconds, or 1 real second at 2x speed. Auto fire starts off in each new run.
Satellite Reserve Battery is a one-time 8,000 Coin purchase. It increases capacity to 2 charges, recharging once per 50 kills. New runs start with 1 charge, and buying it during a run grants no free charge. It works with manual and automatic fire.
Auto Collection Drone is a one-time 5,000 Coin purchase. It collects only Coin from full idle storage, up to twice per day, while your base keeps operating. The quota resets at midnight KST; offline collections settle when you reconnect. Larger storage increases Coin per collection.
Online guests can submit leaderboard scores at game over. Coin, Workshop, idle mode, invasions, and defense history require a GitHub or Kakao account.
Invasion Mode
Choose an idle base on the first screen and attack with plans from Scout through Apocalypse. A paid plan returns its cost after a successful breach and adds a bonus based on defense strength and breach speed. Failure loses the full cost.
A success bonus is available once every rolling 24 hours for each base and plan. All BOT bases share one 24-hour reward slot per plan.
Your own base is available for free training only and does not affect Coin or defense records.
Custom Assault and defense rewards
Custom Assault lets you build up to 120 units and 10 bosses within a 500 Coin budget. Higher budgets raise baseline HP, speed, boss buffs, CC resistance, and the number of enemies that can pressure the field together.
A successful Custom Assault returns its cost and awards up to 60 Coin. The actual bonus uses the same defense-strength and breach-speed formula as Apocalypse and is available once per target base every 24 hours.
When a base defeats a paid invasion, its owner automatically receives 10% of the invasion cost. Payouts and recent results appear in the Defense Report.
While your idle base is active, one bot invasion result per day is added to the Defense Report and successful defense rewards are paid automatically.
Tower awakening
Towers gain mastery from enemies they directly finish. Normal kills grant 1, a boss final death grants 10, and revives or Orbital Strike kills do not count.
Once mastery is full, spend run Gold to awaken the tower. Awakening survives direct level-ups and same-type merges, is saved with the idle base, and works during invasion defense. It does not add a separate idle Coin bonus.
Research the Auto Awakening Device once for 5,000 Coin. It starts disabled. Save your enable switch, minimum remaining Gold, and priority in the Workshop. Settings persist with your account; at most one tower awakens every 0.5 game seconds.
Base mastery requirements: Bow, Ice, Tornado and Sniper 20; Laser and Bomb 30; Dark Star 50. All 11 combos with Ice or Tornado ingredients also require 20 mastery. Slow, freeze and airborne control alone do not grant mastery.
Combining two awakened base towers produces an awakened combo. One awakened ingredient instead grants 25% of required mastery, rounded up. The combo ability replaces ingredient abilities.
Existing bases import recorded base-tower kills once. Missing records start counting after resuming; historical control counts are not imported. Idle time does not generate mastery.
Awakening Catalyst has 5 levels, each reducing required mastery by 2%, up to 10%. Prices are 600 → 900 → 1,200 → 1,500 → 1,800 Coin. Requirements round up; existing mastery and awakening Gold costs are preserved.
Field devices
Use the device box button to install devices on the path. Opening the menu pauses battle. Pick a device, then a highlighted slot or numbered button. Canceling before placement is free.
Shock Mine costs 60 Gold and deals splash damage. Workshop blueprints unlock Armor Breaker (90 Gold) and Emergency Barrier (120 Gold). Breaker temporarily exposes nearby enemies; boss potency and duration are halved. Barrier intercepts 2–4 normal enemies at the exit, but not bosses, and grants no kill rewards.
The base limit is 3 devices, expandable to 5 in Workshop. Bulk Contracts discounts apply. Device Engineering affects newly installed devices only.
Unused devices persist across waves, checkpoints, and idle resumptions. Invasions and training consume independent copies, preserving the original base. New games reset devices. Removing an installed device gives no refund. Devices add no direct idle Coin production.
Target priority
Select a placed tower to change its target priority. Auto targets nearby enemies for Bow, leading enemies for Sniper and control towers, fast or leading enemies for beams, clusters for splash towers, and bosses or high-HP enemies for dark towers.
You can manually choose First, Strong, Finish Weak, Cluster, or Boss First and optionally apply the choice to every current tower of that type. The setting is saved with the idle base and used during invasion defense; older bases use Auto.
Explore next
Tower combinations lists every recipe and role. Visit the FAQ for answers about saving progress and device support.