The player should be careful of the portals, but not base their entire defense around them, as they will frequently shift positions. It is a good idea to get a Cactus in every lane as fast as possible, although it is a good idea to save up at least one in the conveyor belt, in case a Balloon Zombie comes in a lane where there is nothing to stop it. Another good idea is to save up the 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 the player's plants). Use Torchwoods wisely, as they do not work on Cacti, and place Wall-nuts in front of particularly vulnerable portals. If a portal is too close to the left end of the lawn, try planting Wall-nuts or any other defensive plants to stop the zombies from entering the house.
This is what happens if the player's Garden Rake ends up in the wrong place (unless he or she is lucky and gets a Cherry Bomb)
Occasionally, portals may appear in positions where, with the same set of portals in a single row, zombies may not be able to walk on a few squares and any projectiles that were fired (or less likely, zombies) before the portals switched may be trapped in an endless circuit, until the portals move away.
The name "Portal Combat" is a pun based on the video game series Mortal Kombat. The white circular portal is a reference to the latter game series.
It can be also based on the popular game series under the name Portal, given the design of the portals.
The achievementNo Fungus Among Us cannot be achieved in this level, most likely because all the plants available in this mini-game are not mushrooms.
When a Lawn Mower heads towards a portal, it will teleport to the other portal.
Portals will teleport all projectiles, even high spikes which look like they will pass over the portals.
If a Cherry Bomb is planted horizontally adjacent to a portal, there is an occasional glitch where the explosion will go through the portal. If this glitch occurs, the explosion radius will follow the normal rules for passing through portals, but only on the square directly next to the other portal.
Along with Zombiquarium and Beghouled Twist, this level is in a mini-game pack for purchase instead of being in the normal mini-games section in the iPad version.
This is the only level that Zombie Yeti can enter the player's house or modify the Lawn Mowers, which portals may appear everywhere.
A glitch in the iPad version makes the game crash when the first portal is relocated.