This guide breaks down everything added in the Merge Madness update and explains how to play the event efficiently, what to prioritise, and practical tips that actually matter when you’re trying to progress fast. Read the overview first, then jump to the strategy and checklist sections for a step-by-step plan.

The update adds a time-limited Merge Madness event that rewards merging mutated plants and brainrots, a new weather system that influences mutation spawns, 25 new story missions, a Cherry Blossom biome unlocked through missions, two new rebirths, two new fusion brainrots, eight additional base brainrots, a rotating Brainrot of the Week reward, and a number of quality-of-life bug fixes. The event is merge-centric: progress comes from creating mutated merges, not just passive collection.

Merge Madness event

You progress the event by placing two identical mutated units in the Merge Madness interface.

When you place two matching mutated plants or brainrots you get a merged result and event completion progress increases.

The UI tracks event completion and pays out cash and event rewards as you fill the meter.

Mutations are the required currency for event progress — plain units do not count unless they carry a mutation.

Mutations and the weather system

Weather spawns run globally on the map and affect mutation chances. For example, storms increase the chance of electrified mutations.

There are several mutation types (frozen, neon, electrified, etc.). Some are rarer and only appear during specific weather or in higher tiers.

To maximise mutation acquisition, time your grinding runs around the weather that boosts the mutation you need. If a storm gives electrified units, farm aggressively during the storm window.

Weather is temporary. If you don’t farm a desirable mutation during its window, your next opportunity will be the next weather cycle.

Brainrot of the Week and fusion brainrots

The Brainrot of the Week rotates; locating or finding that specific brainrot during the event gives bonus rewards. Always check the event panel or announcement to see which brainrot is currently featured.

Fusion brainrots are special, higher-tier variants that usually require more advanced merges or event activity to produce. They often give larger progression chunks or high value when used as the weekly target.

Rebirths and long-term progression

The update adds two new rebirths. Rebirths reset some progress but grant long-term multipliers or permanent bonuses that make subsequent runs faster.

If you aim to climb leaderboards or maximise long-term efficiency, plan rebirth timing so you spend before resetting on event milestones you can’t reclaim easily. In short: don’t rebirth mid-event unless you’ll immediately benefit from the rebirth bonus for the remaining event time.

Cherry Blossom biome and story missions

Complete the new 25 missions to unlock the Cherry Blossom biome. The biome contains themed rewards and often spawns event-friendly units or themed resources.

Missions also reward XP potions, merge resources, and occasionally mutation chances; prioritise mission tasks that are compatible with your daily goals to avoid wasted runs.

Practical play strategy

Check the weather first. If it’s the mutation you need, prioritise active farming now. If not, finish mission objectives or farm generic resources.

Top up XP potions. Use XP potions to increase the chance of higher-tier spawns in your merge pools; some merges require level thresholds for better results.

Hunt for the Brainrot of the Week. If the weekly brainrot lines up with the event target or your current merges, focus a session on obtaining it — the reward bump is usually worth the detour.

Merge mutated pairs in the event UI. Don’t merge blindly in your base; only place pairs that match the event requirements (identical mutated units) to get event progress.

Complete short missions between weather cycles. Use missions to convert downtime into progress and to acquire the Cherry Blossom unlock faster.

Save rarer fusion outputs for the weekly target or later stages where they give bigger event progress increments.

Merging tips

Only identical mutated pairs count. If you have one frozen and one neon of the same base, that does not count — you need two units with the same mutation.

Plan merge pipelines. Keep a “mutation staging” area so you can quickly pair identical mutated units when you find a match. This reduces accidental merges that waste rare units.

Don’t auto-merge everything. Auto-merge systems are convenient, but they can consume a valuable mutated unit that you should have matched to the event pair first. Disable or control auto-merge during the event.

Use XP potions strategically. If the event requires higher tier mutated versions, pop an XP potion before a big farming spree to increase the spawn of higher rarity units.

Farming routes and resource flow

Weather windows = hotspot runs. Start a run at the beginning of the weather cycle (if visible) and run short, repeated sessions focusing on spawn nodes that historically produce the mutated types.

Mission + farm loops. Knock out 2–3 quick missions during downtime then jump back into mutation farming for the next weather window.

Prioritise inventory slots. Keep space free for mutated drops; full inventories cause missed mutation drops.

The Merge Madness update rewards planning and timing more than brute force grinding. Focus on weather windows, control your merges, use XP potions when you want higher quality spawns, and keep one eye on the Brainrot of the Week. If you treat the event as a set of short, targeted farming sessions rather than endless auto-play, you’ll unlock the Cherry Blossom biome, collect fusion brainrots, and get the best event rewards in far less time.