Portal Combat

Portal Combat is a Night Mini-game without Graves. Instead, there are two pairs of connected Portals, which Zombies and projectiles will pass through.

Zombies

 * Zombie
 * Buckethead Zombie
 * Football Zombie
 * Balloon Zombie

Strategy
This is a Conveyor-Belt Level, where the Plants that you recieve are the Peashooter, Repeater, Torchwood, Cherry Bomb, Cactus, and Wall-nut.

Be careful of the Portals, but don't base your entire defense around them, as they will frequently shift positions. Try to get a Cactus in every lane as fast as you can, although it is a good idea to save up at least one in the Conveyor Belt in case a Balloon Zombie comes where there isn't anything to stop it. Save up your Cherry Bombs whenever they appear, and only use them when you have to (e.g. on Football Zombies, or if a Portal appears in the back, behind most of your plants). Use your Torchwood wisely, remembering that it doesn't work on Cacti, and place Wall-nuts in front of particularly vunerable Portals, and you should win relatively easily.

Trivia

 * Occasionally, portals may appear in positions where, with multiple portals in a single row, zombies may not be able to walk on a few squares and any projectiles that were fired before the portals switched may be trapped in an endless circuit until the portals move away.