In 2000, Folding@home was released online—it was an early experiment in a field called “distributed computing,” where users would effectively donate their computer’s time and energy to work on a big problem with other computers around the globe. Together, these users’ computers began figuring out protein structures, and as the effort isn’t restricted to lab space as this kind of project usually is, it’s still running today.

Distributed computing continues to be a valuable asset for researchers who are trying to solve problems that any one computer would take forever to understand. But there are limitations. If the problem is visual, and you can’t teach a computer to recognize solutions, rather than using computers the better option might be letting people donate their own time and brainpower instead.

Foldit was released in 2008, and let users play with proteins themselves, trying to figure out the ways proteins’ chemistry lets them fold up in 3D space. People started playing Foldit like a game, and players started doing better than computers, folding complicated structures, and solving longstanding protein puzzles.

Now, Cancer Research UK is following in the tradition of crowdsourcing medical research with a mobile game called Reverse the Odds. There are three layers of “game” here. The player starts out looking at a 5-by-5 landscape of grey tiles (calcified, like a tumor—the metaphor is not subtle) which she is then tasked with revitalizing with potions, earned by examining tissue slides from actual cancer patients, and then used by playing a Reversi-type game against a cutesy gray AI character. Like Candy Crush, different goals change the way the mini-game is played: sometimes the goal is to reverse more tiles, sometimes specific tiles, and other times it’s a specific number of tiles in one move.

When I sit down with my phone to play Reverse the Odds, I find myself skipping over the land-revitalization and the Reversi clone and just running through slide after slide. They have hundreds of slides from hundreds of different cancer patients being analyzed by players all day long. The goal isn’t to influence individual treatments, but to find correlations between the presence of certain cells and how well patients respond to treatment.

All I’m doing is looking at how many cells on the slide have been dyed blue and how strong the coloration is. It’s a task that I can do while slouching, or in between stirring the pot my dinner is cooking in, but it feels like I’m helping. That ends up being enough to keep me playing.

Reverse the Odds is available for free on iOS and Android devices