Overall, the Defense Crawler is only useful when the player is at least level 10 (or at the very least Level 4, at which point both Guardian Cannons and Missile Turrets are unlocked), as the first units are impossible to use in a successful strategy. The crawler can be used very well in holding ground, such as near a TCN Node, capable of keeping enemy units suppressed for a very long time. When upgraded with Defensive matrix, the crawler gains a shield when deployed, or the Mobility matrix, which gives a shield when packed up. Each hold 1000 extra health, and protect anyone inside the radius. When in tier 3, the shield can be upgraded to hold 2000 health, using the Enhanced shields upgrade. combined with Enhanced repairs, which give the crawler double repair speed and increased repair radi