When performing Burrow, Knuckles dives into the ground and tunnels just below the surface. Eventually, Knuckles will resurface and shoot himself into the air with an uppercut. The latter part of the move will damage any enemies Knuckles comes in contact with. In gameplay, the move can only be performed on marked areas on the ground.
Sonic Boom: Rise of Lyric
In Sonic Boom: Rise of Lyric, Burrow serves as one of Knuckles' character-exclusive moves. With it, Knuckles can dodge attacks by diving underground and damage enemies upon emerging. When emerging from using Burrow, Knuckles leaps into the air, and can even perform the Double Jump, which can be used to reach higher areas. It is also the only move which can force the underground pests in Hayward's side quest to the surface. In gameplay, it can only be used on patches with purple dirt.
To perform Burrow in gameplay, the player must press while standing on (or above) diggable ground. As long as is held, Knuckles remains underground. The player can also control Knuckles' tunneling movements with the Left Stick. To make KNuckles resurface, the player must release .
Sonic Boom: Shattered Crystal
In gameplay, Burrow can only be used at spots marked with a mound surrounded by a red hoop. When using Burrow, the player enters an underground path that leads from one entrance point to another. However, Knuckles can only use Burrow for short time which is displayed by a gauge in the upper right corner of the screen that drains while Knuckles is underground. If the gauge empties while underground, or if Knuckles takes damage, he will return to the starting point above ground.
To perform Burrow in gameplay, the player must press while standing on an entrance point. The player can then control Knuckles' movements with the control stick. Using Sprint underground will make Knuckles move faster, but it also drains the time gauge faster. Occasionally, the player will come across mine-like objects while burrowing.
Sonic Boom: Fire & Ice
Mechanics-wise, Burrow and its underground sections are the same as in Sonic Boom: Shattered Crystal, except Knuckles can stay underground without a set time limiting his presence underneath the surface. Regardless, if Knuckles takes damage, he will return to the starting point above ground. In gameplay, it can only be used at brown dirt spots marked with a crossed pickaxe and shovel. Also, while using Burrow with Fire/Ice Mode active, the player can form loops underground called Burrow Loops with Knuckles' energy trail to create an explosion of fire/ice that damages anything within the loops.
To perform Burrow in gameplay, the player must press while standing on an entrance point. The player can then control Knuckles' movements with the control stick. By pressing while underground, the player can use Fast Burrow to make Knuckles move faster. New obstacles encountered while burrowing in this game include moving spike blocks, underground enemies, and water blocks which the player can freeze or melt with Fire/Ice Mode.
- Sanzaru Games (27 September 2016). Sonic Boom: Fire & Ice. Nintendo 3DS. Sega. Area/level: Lost Pyramid. "Hint: Burrow Loop - Make a circle using Knuckles' Burrow to destroy everything inside the loop!"
- Sanzaru Games (27 September 2016). Sonic Boom: Fire & Ice. Nintendo 3DS. Sega. Area/level: Lost Pyramid. "Hint: Fast Burrow - Hold while burrowing for an added speed boost!"