Crawler Strategy: Splitting Segments and Managing Mushrooms

Updated October 2026

Crawler is a shooting game where every hit changes the board. Each segment you destroy leaves a mushroom behind, each mushroom changes the path of every segment that meets it, and a careless burst of fire can turn one predictable crawler into several pieces arriving from different directions. This guide explains the movement rules exactly, shows where the real danger zone is, breaks down the scoring and offers a plan for keeping waves under control as they get longer and faster.

The field and your shooter

The field is a grid 13 columns wide and 18 rows tall. Your shooter sits on the second row from the bottom and can only move left and right. Touch anywhere on the field and hold: the shooter glides toward your finger's horizontal position, and for as long as your finger stays down it fires automatically, one shot every 0.22 seconds, a little over four shots per second. Lift your finger and it stops both moving and firing.

The glide is smooth rather than instant, so the shooter lags a fraction of a second behind a fast finger. Keep your movements short and deliberate; a long swipe across the whole field leaves your shots trailing behind you.

Shots fly straight up. On a typical 390-pixel-wide phone each cell is about 26 pixels (our measurement) and a shot travels a little over 12 cells per second, so it needs roughly a second to reach the upper rows. Each shot stops at the first thing it meets in its column: a crawler segment or a mushroom.

How the crawler moves

A crawler is a line of segments that moves in steps. On each step, every segment tries to move one cell in its current direction. If the cell ahead is beyond the edge of the field or holds a mushroom, the segment does not move; instead, on its next step it drops one row and turns around. That is the whole rule, and it has three consequences worth remembering:

• Mushrooms speed up the descent. In an empty row a segment walks all the way across before turning. In a row full of mushrooms it turns almost immediately and keeps dropping.
• Dropping costs a step. A blocked segment spends one step standing still and one step moving down, so a crawler snaking through a crowded area falls steadily but does not cover ground sideways.
• The bottom is not the end. A segment that drops past the last row reappears just above the bottom zone, on the fifth row from the bottom, and keeps patrolling the lowest rows until you destroy it.

Steps come every 0.48 seconds in wave 1, about two cells per second. Each wave shortens the gap by 0.03 seconds until it reaches 0.16 seconds, about six cells per second, in wave 12. After that every wave is another 6 percent faster with no top speed: about 7.5 cells per second in wave 15 and 10 in wave 20, so sooner or later the crawler outpaces anyone.

What splitting does

When a shot hits a segment, three things happen at once. The segment is destroyed, a fresh mushroom with full strength appears in the cell where it was, and the crawler is divided at that point. The part in front keeps going as before. The part behind becomes a separate crawler and reverses its direction, so it moves away from the new mushroom rather than into it.

The new mushroom matters as much as the split. It sits exactly in the row the crawler was travelling along, so later segments on that row will meet it and drop. A good habit is to think about where the mushroom will land before you fire: a hit near the edges creates a blocker that segments meet anyway, while a hit in the middle of the field creates a new turning point in an area that was clear.

One segment of every crawler is its head, drawn with a face. On the original crawler it is the front segment; on a piece split off behind a hit it is the segment that was next to the hit, which after the reversal sits at that piece's rear. Heads are worth 100 points; every other segment is worth 10. Because every split creates a new piece, it also creates a new head. Picking off the head of a short piece is therefore much better value than shooting body segments of a long one.

Mushrooms: walls, shields and points

Each wave starts with a fresh scatter of mushrooms between the third row from the top and the row just above the bottom zone, a few more each wave. A mushroom takes four hits to destroy and shrinks and darkens as it is damaged; clearing one is worth a single point. Its real value is positional.

• Mushrooms in your column block your shots. If a mushroom sits directly above you, every shot you fire is spent on it before anything higher can be hit. Either move one column over or spend the four hits to clear it.
• Mushrooms to the side are free terrain. They turn segments and send them down, which you do not always want, but they also make paths predictable. Clearing every mushroom wastes shots and time.
• Mushrooms you create are fresh. Every kill adds a full-strength mushroom, so a long fight in one column builds a stack of blockers there. Shift your position from time to time so your own kills do not wall off your line of fire.

Where the danger really is

A segment only hurts you when it is on your shooter's own row and in the same column as the shooter. A segment on the row above or below you is harmless for the moment, which is useful to know when segments are cycling through the bottom rows. The threat is a segment that is about to step sideways along your row into your column, or one that is about to drop into your row right where you are standing.

When a segment reaches your row, watch its direction and move away from it, or better, move toward the column it has just left; segments never move backward without first dropping a row. Your shots fired from directly beneath a segment on the row above will also hit it on the way up, often before it can come down.

Losing a life pulls every segment that is in the bottom four rows at that moment back to the top-left corner, where they line up and enter the field again, and returns the shooter to the centre. No points are awarded for them and they still have to be shot before the wave can end. Segments higher up stay where they are. You have three lives in total.

Waves and the score curve

A wave ends when every segment has been shot. Clearing it adds a bonus of 100 points multiplied by the wave number, so wave 3 pays 300 and wave 10 pays 1,000. The next wave starts after a short pause with new mushrooms and a longer crawler: 8 segments in wave 1, two more each wave, up to a maximum of 18 from wave 6.

In practice that gives a score that is driven mostly by heads and wave bonuses. A useful mental model:

1. Body segments are small change. Shoot them when they are in your way.
2. Heads are the main income. When a split produces a short piece near the bottom, its head is close and cheap to reach.
3. Wave bonuses grow every wave, so survival is worth more than squeezing every point out of the current wave.

A practical plan for each wave

1. Open fire early, high and central. At the start of a wave the crawler enters along the top row. Meeting it while it is still high gives your shots time to travel and keeps the fight away from your row.
2. Lead your shots. In wave 1 a segment moves about two cells while your shot climbs from the bottom to the upper rows, by our arithmetic from the game's constants. Aim a little ahead of a moving segment, more so as waves speed up.
3. Keep your column clear. Before the crawler arrives, spend a few shots removing any mushroom directly above your favourite position.
4. Settle the bottom zone first. Any segment cycling through the lowest rows is the immediate threat. Deal with it before you return to targets higher up.
5. Move in short hops. Small finger movements keep the shooter under your control and your stream of shots tight.

Your best score is stored on your device, and any score above zero can be saved to the Hall of Fame when the run ends.