Merge Bastion

A merge tower defense where your defence is built by combining, not buying. Pick a robot role and recruit it in the barracks: Assault for heavy direct damage, Cryo to slow the horde, Tesla to stun it, Corroder to eat through armor, or Artillery for splash shells that stagger the ground but cannot hit fliers. Drag two units of the same tier together to fuse them into the next tier, whatever their roles (the receiving robot keeps its role), and from tier three every robot fires its own charged skill, and deploy the result onto a glowing pad on the road where it fires on its own. Eight tiers run from a cheap Scout to a Sentinel, and the top two change role rather than just numbers: the Vanguard's shots splash across a cluster, and the Sentinel drags everything inside its field to a crawl. Enemies arrive in waves that keep escalating, and every wave rolls new modifiers that combine rather than just stack numbers — Swarm, Armored, Hasted, Shielded, Regenerating, Volatile, Relentless and Focused. New enemy types unlock as you go: splitters that break into two on death, flyers that ignore the road entirely, and suppressors that pulse shields onto the walkers around them. Your side does the stunning: Tesla shots stun briefly and Artillery shells stagger whatever they land on, and a stunned walker shrugs off the next stun for a moment. Every tenth wave the whole battlefield changes biome, from the neon city to a frozen outpost, ash wastes and a deep reactor, and every fifth wave the road itself is redrawn into one of fourteen long, winding layouts dealt in a new order every run. Every road carries a fortified gate that holds the horde until they batter it down, and forked roads add a junction switch: tap it to send the next walkers down the long gated branch or the short open one. Your deployed units move to the new pads, so every road asks for a different layout. Your Bastion starts with twenty hit points and nothing heals it back during a run, so every enemy that reaches it is a permanent loss.

How to play

Start with four tier-one Scouts in the barracks: two Assault, one Cryo and one Tesla. Drag one onto another to fuse them, then drag the result onto a glowing pad on the road to deploy it, where it picks the closest enemy in range and fires by itself. Pick a role in the recruit bar (Assault, Cryo, Tesla, Corroder or Artillery), then RECRUIT to add a tier-one robot of that role; any two robots of the same tier merge, and keep fusing: two of a tier always make one of the next. Between waves the ROBOTS workshop refits any robot to another role for free. Each recruit in the same wave costs four coins more than the last, and the price resets when the next prep starts, so merging what you already hold is usually the cheaper move. Dropping a unit onto an already deployed unit of the same tier upgrades that unit in place instead of taking a new pad. Read the modifier chips under the wave label before you commit, because they decide how the wave fights back: Armored means raw damage stops working, Shielded means bursts, Regenerating means you must out-sustain it, and Volatile means every death sends the walkers around it into a short sprint. You can move a deployed unit by dragging it to another free pad. Between waves there is no countdown: plan as long as you like, and START WAVE pays an immediate coin bonus. SELL mode turns taps into refunds at sixty percent of a unit's value, which is how you rebalance a garrison that fell behind. A gate on the road stops walkers until they break it, and it is rebuilt between waves. On a forked road, tap the switch at the junction to choose which branch the next enemies take; the closed branch is marked with a red X. Every fifth wave sends a boss that hits the Bastion for ten, and the BOSS IN counter at the top tells you how far away it is. Killing a boss pays a coin bounty on the spot and banks shards for permanent upgrades. When a run ends you are paid in shards, and the UPGRADES button on the panel spends them on permanent upgrades: a larger starting garrison, a tougher Bastion, more starting coins, extra damage, faster fire and an early deploy. Your shard balance and upgrade levels are saved in this browser and carry into every later run, so a defeat clears the battlefield but never your upgrades. Come back each day for a daily supply drop of shards; the reward grows over a seven-day streak and resets if you miss a day. The x2 button at the top right of the battlefield doubles the game speed.

Controls

Everything is a drag. Press and hold a unit in the barracks, or a deployed unit on a pad, then release it on an empty pad to deploy, on an identical unit to merge, or on an occupied cell to move. Buttons: RECRUIT buys a tier-one unit, MERGE ALL fuses every matching pair in the barracks at once after an eighteen second cooldown, SELL toggles sell mode, START WAVE launches the next wave for a bonus, and the x1/x2 toggle on the battlefield switches game speed. Esc or the PAUSE button pauses, and the pause menu toggles sound.

Tips and strategy

• Mix your roles: Cryo slows the horde so everything else gets more shots, Artillery shreds packed groups, Tesla stuns the front runner and Corroder strips armor. Any two robots of the same tier merge.
• RECRUIT gets pricier with every buy inside the same wave. Buy a few at the start of prep, merge them, and wait for the price to reset rather than spamming the button mid-wave.
• Use SELL mode the moment your garrison falls behind the wave curve: sixty percent of a unit's value back beats holding a tier that is too weak to matter.
• Read the modifier chips before you build. Armored and Regenerating both punish a single high-damage unit, so a spread of mid tiers beats one big one on those waves.
• The fifth wave of every fifth block is a boss that deals ten damage to the Bastion. Save a Warden for it rather than spreading damage across several mid tiers.

Merge Bastion FAQ

Privacy and saves

The game runs entirely in your browser. Your best wave, shard balance and permanent upgrade levels are stored only in this browser's localStorage, together with a flag recording that you have already seen the tutorial, the highest tier you have unlocked and the date and streak of your last daily supply drop. No account, server or third-party ad network is used on this site.

A Quokka Labs original browser game · Free to play · No download