MegaBonk is a roguelike action game where players unlock various items by completing specific challenges. The Cactus item is a defensive relic that shoots spikes when you take damage, with the spike damage scaling based on your Thorns stat. It creates a protective perimeter around your character by reflecting damage back to attackers. Unlocking it requires a focused strategy on dealing Thorns damage to specific enemies.

Best Thorns Build Cactus

Requirements for Unlocking the Cactus

To unlock the Cactus, you must complete the challenge: Kill 100 cactus enemies using Thorns damage (not direct weapon hits or other damage types). This must be done on the Desert map, as cactus enemies primarily spawn there.

  • Map Selection: Choose Desert 1 (or higher Desert levels if available in your progression). Cactus enemies start spawning in waves:
    • Basic mobs from the start.
    • A new type after 1 minute.
    • A third type (including more cacti) after 2 minutes.
  • Damage Type: Only Thorns damage counts toward the kills. Thorns is a stat that reflects a portion of incoming damage back to enemies when they hit you.
  • Post-Challenge: After achieving 100 kills, the item becomes available for purchase or unlock in the game's shop or relic menu using in-game currency or resources (details may vary by patch, but it's typically straightforward once the quest is complete).

This challenge can take multiple runs to complete, as progress carries over between attempts.

Recommended Strategy

The key is to survive long enough for cactus enemies to spawn in large numbers while maximizing Thorns activations. Here's a step-by-step approach:

  1. Game Mode: Play in Hyper Mode if unlocked, as it provides double XP and can speed up enemy spawns or resource gathering for related tombs/quests.
  2. Character Selection: Start with Athena if available, as her abilities synergize well with defensive builds and spamming early waves on Desert 1.
  3. Survival Focus: Aim to last at least 2-3 minutes per run to encounter the later cactus waves. Repeat runs until you hit 100 kills.
  4. Enemy Targeting: Let cactus enemies hit you to trigger Thorns. Avoid killing them too quickly with weapons—position yourself to take hits without dying.
  5. Patience and Runs: This may require 5-10 runs or more, depending on your build efficiency. Track progress in the game's challenge menu.

Best Build for Thorns Damage

Cactus Swarm Megabonk

Build around tankiness to take hits and reflect damage. Prioritize upgrades that boost Thorns while sustaining your health.

Core Stats and Upgrades

  • Thorns: Max this out early—it's essential for the kills to count.
  • Armor: Increases survivability so you can take more hits.
  • Regeneration and Life Steal: Keeps you alive during enemy swarms.
  • Avoid Evasion: It prevents hits from landing, which stops Thorns from activating.

Recommended Items/Relics (If Unlocked)

  • Any items that boost Thorns reflection (e.g., spike-related or defensive auras).
  • Health-boosting relics to extend run time.
  • Avoid offensive weapons that clear enemies too fast.

Sample Early Game Priorities

  1. Pick up any Thorns upgrade at the first level-up.
  2. Grab armor or regen next.
  3. Position in open areas to attract cactus mobs without getting overwhelmed.

Tips and Common Mistakes

  • Don't Use Weapons on Cacti: Direct damage won't count—rely purely on Thorns.
  • Wave Timing: Push past the 2-minute mark for optimal spawns.
  • Difficulty Scaling: If Normal mode is too slow, switch to higher difficulties for faster enemy density, but ensure you can survive.
  • Progress Tracking: Check the in-game quest log after each run to see your kill count.
  • Patches and Updates: This guide is based on the latest info as of October 2025; check official patch notes for changes.

Once unlocked, the Cactus item is great for defensive builds in later runs.