- 4 Metal One Horns spawn after 20 seconds600f, delay 43.33 seconds1,300f.
- 1 Cosmic Cyclone spawns as the boss after 6.67 seconds200f.
Spawn a couple of Psychocats to stall the Cyclone as you save up money. Once the Metal One Horn spawns, lure the Cyclone to about the middle of the stage, here you want to start to build your stack, start spawning all units except your meatshields.
As your stack starts to build, the Metal One Horn will close the gap. When he reaches the Cyclone, start meatshielding and spamming your critical hitters until they crit, then stop meatshielding and repeat.
Make sure to summon some units who can knockback aliens to regain any lost terrain, or just make sure to deal enough damage, just do not summon meatshields or critters in this phase.
Based on the quality and quantity of your critters, it may take a couple of attempts, but, as long as you own Waitress or another unit with guaranteed crit chance and you use the Slow Beam to keep everyone in place during the animation, RNG will be unable to ruin your attempt.