Presents are wrapped, eggs are nogged, kids are on Christmas break, and two of this year’s biggest game stars have come together in one app filled with underground sewers and transportation tubes. How merry!

Especially considering it’s free.

The resulting Disney interactive mash-up–Where’s My Holiday?–sees Swampy from Where’s My Water? and Perry from Where’s My Perry? plunged into holiday-themed levels where kids are challenged to dig through dirt, avoid algae, and manipulate physics in the form of steam and ice to help the shower-happy alligator and semi-aquatic super sleuth thwart rubber ducks and Doofenschmirtz.

Each game–think lite versions–squeezes Christmas cheer into six levels with mission names like “Red Nosed” and “Tree of Lights,” and levels can only be unlocked by completing the previous one.

One warning: though garlands made from moss and hidden gnomes are festive, the incessant pop-up in-app purchase ads are not. Then again, for novelty’s sake, this free (hooray!) holiday treat is worth the download as long as you remember to turn off the automatic download option in your device’s “settings” panel first.

You should do that anyway. Consider it my Christmas gift to you. –Pilar

Download Where’s My Holiday? for iPhone and iPad on iTunes for free! Or download from Google Play for Android devices.