Circulate flips puzzle games upside down.

Casual games are big business. They can run on pretty much any PC made in the last decade, provide hours of lighthearted enjoyment, and are usually quite affordable. Best of all, they don’t require the sort of time commitments associated with big budget titles. You can rip through a level before work, during your lunch break, or mess around for 10 minutes before bed. Perhaps that’s why Circulate, a charming little puzzler from Pi Eye Games and Slave Circus Entertainment, is such fun. Whatever the reason, if you’re the type who enjoys killing time during your coffee break, you’ll get some mileage out of this colorful little diversion.

Circulate shares some similarity with other, more well-known puzzle games. On some boards, you match like-colored balls in the shortest period of time to earn yourself gold stars. Other times you must rotate the circular playing field to coax the marbles into their designated containers. Just when you think you’re getting the hang of it, a new mechanic is thrown at you to change things up. There are hot and cold marbles that melt when they collide. There are metallic ball bearings that you can lead in different directions with powered magnets. You can even detonate bombs, slide wooden planks, and employ mover marbles to nudge your way to victory. There’s plenty of variety to be had throughout the Circulate’s 120 vibrant single-player levels. To experience them all, you’ll need to accumulate enough gold stars on earlier boards to unlock the more challenging scenarios.

To help the uninitiated, the game provides plenty of usable hints at the start of each round. If you find yourself stuck on a challenging puzzle, you are allowed to slow down the game’s “gravity” setting to ease the difficulty, and also skip ahead to test out other boards. You can also replay levels you’ve already completed to increase your score and earn more stars. There’s also some in-game documentation if you want to read up on the various items and objectives you’ll face.