I’m not going to lie: the first thought that popped into my head when I started to peruse the Instamatch app was “what a waste of time.’

Then I spent an hour happily playing with it. Waste of time, indeed. Instamatch is memory concentration game that integrates with the Instagram, the popular iPhone app,  to create a card-matching memory game.

It works like this: Pick a game mode that either chooses from a pre-selected set of photos or from your own Instagram photos. (The game is not officially associated with the photo-sharing app, by the way). The goal is to match as many pairs of photos as possible–as quickly as possible.

If you’re choosing from the game’s Instagram library that typically means picking pairs of similar photos. For example, if you play a game that filters your photo choices into the “nature” category, you’ll likely be shown one photo of a waterfall and then have to match it with a similar photo depicting a different waterfall. Or, if you decide to play the game using your own photos, you’ll be tasked to match pairs of the same photo.

There are five pre-selected themes–the aforementioned Nature as well as World Wonders, Cities and of the course, what seem to be the two most favorite photo categories on the entire Internet: Animals and Food. You can play by yourself or play with up to four other users (the app is also available for the iPhone, which supports a two-player game). You can also customize your own picture set by typing in a subject (cats, coffee, cars, etc) and the game brings up pictures that sport a hashtag that matches your theme (this can be a little confusing–I typed in “shoes” and in addition to images of sandals, sneakers and boots, got pictures of a ring and someone lying on a sidewalk. But that’s the conundrum of the hashtag–not an actual fault with the fame). And, if you’re logged into your own Instagram account, it’ll pull hashtagged pics from your friend’s collections as well.

The game is playable in three levels – “easy,” “normal” and “hard”–and it’s the last category where things get really interesting. The goal at this level is to match up 15 different pairs of moving cards. That’s right–just as soon as you think you’ve memorized exactly where that pie picture is–oops, it’s switched places with the cake.