Corrosive Glue (BTD6)

"Glued Bloons pop one layer every few seconds."

- In-game description

Corrosive Glue returns as the 2nd upgrade of Path 1 for the Glue Gunner in Bloons TD 6. It allows the Glue Gunner to deal damage to bloons over time while glued, but now glue corrodes per 2.3s, which in total corrodes up to 4 layers (10 with Stickier Glue). Unlike BTD5, having this upgrade or MOAB Glue lets the Glue Gunner target MOAB-class bloons. Blimps affected by Corrosive Glue do take damage over time, but are not slowed down.

It costs $255 on Easy, $300 on Medium, $325 on Hard, and $360 on Impoppable.

Description
Corrosive Glue will start damaging the glued bloons after 2.3 seconds and by 1 layer per that same time interval. Due to the previous upgrade, this will persist even if the current layer is popped. The base glue will last long enough to apply 4 layers of damage. Adding Stickier Glue will increase this to 10.

The Glue Gunner gains a purple protective suit and green goggles. When combined with other tier 2 crosspaths, half of the suit will be purple and the other half will be the other path's respective color. When applied as a secondary crosspath for tier 3 and 4 upgrades, their respective suits gain a thin, purple, vertical stripe on the middle of their headgear.

Summary
Corrosive Glue is useful as an early-game and mid-game option for handling normal bloons, especially early strong bloons such as Lead Bloons. It deals damage-over-time, which helps break down the affected bloons. In addition, the bloons will be soaked with glue for a considerable amount of time, slowing them down while simultaneously gradually chipping down layers over time. This can help assist other towers to destroy the affected bloons more easily. Corrosive Glue can be added on top of Glue Hose or Glue Strike to maximize the amount of soaked bloons. More importantly, this allows the debuff of Glue Strike and Glue Storm abilities to affect MOAB-class bloons.

However, Glue Gunners with Corrosive Glue fall back severely in late-game and become a nuisance with MOAB Glue, as Corrosive Glue will have the potential to override the blimp slowdown power of MOAB Glue. Corrosive Glue is not an entirely useless upgrade in the late-game, however, as a 2-4-0 Glue Strike and 2-5-0 Glue Storm are the only crosspaths that allow their abilities to attack MOAB-class bloons and thereby apply +1 damage vulnerability to affected blimps, and the infinite pierce of both abilities can be used as a damage counter to Round 101+ hyperclumped Purples.

Tips

 * This is useful for helping deal with large waves of lower-tier bloons, as while dealing damage slowly, the widespread effect can help whittle down clumps. Its particularly good at dealing with clumps of Pinks and Purples.
 * Corrosive Glue helps deal with Leads, and is one of the cheaper upgrades able to do so.
 * It is very effective when used with Glue Strike or Glue Storm, as the sheer number of bloons being glued will cause it to do fairly massive damage, which can help prevent your other towers from being overwhelmed. In addition, this crosspath will enable the glue from these abilities to stick to MOAB-class bloons, making them take extra damage.
 * This upgrade is actually usually seen as a downgrade in the later rounds. This is primarily because of the added effect of now affecting MOAB class bloons. Because it deals almost no damage to them and doesn't slow or soak through, it ends up wasting time and pierce gluing them, possibly letting bloons sneak through. Another issue is it can take priority over other glues, such as a MOAB Glue. Don't buy this upgrade if planning to use other glue gunners in tandem. Should almost always be ignored in C.H.I.M.P.S. as it will end up causing issues in the late game unless used as a 2/4+/0 glue.
 * Another issue with the upgrade is it can easily lead to regrow farms. Comboing with a Grow Blocker can help alleviate this problem to an extent.

Trivia

 * The Corrosive Glue artwork is shared with Glue Splatter and Stronger Glue, except with different color schemes.
 * The way that Corrosive Glue deals with bloon hitboxes is modified when buying this upgrade. Instead of checking for the bloon's central hitbox like other Glue Gunners would, Corrosive Glue checks for the entire bloon's hitbox before attacking. The same applies with MOAB Glue.