Been a while since I have seen a deal for this game and this seems to be the cheapest price.
EDIT: No longer £9.89 @ 365games. Thanks to @Curlynob for pointing out that Base.com now has this game for £10.99.Base.com
Earth Defense Force 2 Invaders from Planet Space sends the player into high-flying, explosive battles against giant monsters with a classic kaiju/b-movie aesthetic! Praised as the 'best game in the series', Invaders from Planet Space takes the battle online with up to four player co-op and the addition of the unique Air Raider class! Call in huge air strikes or mount the offensive in heavily armored vehicles for a new way to squash the hordes of alien bugs!
Three unique classes: ranger, pale wing, and the all-new air raider!
Take the fight online with three friends in co-op action!
Utilise hundreds of weapons, gadgets, and vehicles, from rifles and grenades to tanks and helicopters!
Stockpile weapons in your base then customise your load-out for the next mission!
Fight through nearly 80 unique missions in single player or online coop!
Call in huge airstrikes or command armoured vehicles like tanks and troop transport!