KingsIsle Entertainment today officially launched Grub Guardian, an iOS and open web “satellite” game tied to its popular kid-friendly massively-multiplayer online title Wizard 101.

The game is a tower defense (in this case, “guardian defense”) title where players position guardian animals around a map, which then snipe enemies as they try to steal a bowl of food at the end of the winding path. Players level up their mythical guardians using the in-game currency earned by wiping out enemies. Aside from the generic animals, players also play a unique guardian who earns experience across levels.

Grub Guardian can be played as its own game, but it’s also designed to serve as an extension of the Wizard101 universe. Players with active Wizard101 accounts can use their in-game pet as the unique guardian in Grub Guardian. If this players pursue this option, the experience their pet earns in Grub Guardian will carry back over to Wizard101. Likewise, players will be able to access premium items from the in-game store if they’re using their Wizard101 pet.

Reading between the lines, this means Grub Guardian is a clever way for KingsIsle to bring in new players into the Wizard101 world. According to KingsIsle VP of Marketing Fred Howard, Grub Guardian’s inclusion of the Wizard101 makes the game appealing for casual and core gamers (both of which are strong populations in the MMO). “The pet system is really complex,” he tells us. “For the casual player, it’s a lot of fun with minigames. But for the core players there’s a whole genetic code behind the pets so you can hatch them and have the genetic code pass over. You can create new hybrid pets and have them get buffed up.”

When asked if KingsIsle Entertainment is planning to launch more satellite titles for either Wizard101 or the newly-launched Pirate101, Howard doesn’t go into detail but says, “we see a lot of opportunity in this space… we can’t talk about our road map, but it’s safe to assume this is the first of many to come.”

Grub Guardian is available for free on iTunes, free to play on the open web and can also be played on Android web browsers.