The match starts on two ISA Intruder platforms descending to the planet surface of Helghan. After time has passed, the Intruders will drop off the combatants onto the Helghan battlefield. After a few missiles destroy part the area, a few Pipo Monkeys can be seen running around, and Specter piloting a Goliath appears. The stage then transforms into a more tropical setting and the Goliath proceeds to destroy the Arc Towers, then turns its attention to the players. At the very end of the match, it appears that the Goliath is destroyed by the ISA.
Characters appearing in stage
This stage starts with a remixed version of "Don't Mess With The MAWLR!" by Joris de Man from the Killzone 3 soundtrack, before switching to an original track based off of "Specter's Theme" by Soichi Terada from Ape Escape and the PSP remake Ape Escape: On the Loose.
Invasion - Killzone
Invasion - Ape Escape
- Invasion, along with Alden's Tower and Stowaways are the only stages with pitfall hazards.
- Invasion is the last non-DLC stage to be revealed.
- This is one of only two stage that descends, the other being Fearless.
- This stage appears to be based on Corinth River, the first level in Killzone 2.
- In the skies of the background of the stage, you can see an area known as the Peak Point Matrix, Specter's secret hideout and final boss arena from Ape Escape.
- Invasion is one of five stages where an E-rated series and an M-rated series cross over, the others being Hades, Dojo, Time Station, and Franzea.
- After a while, a Pipo Monkey inside a metal cage may appear.