Great Filter

Great Filter is a 2D top-down strategy game with 46 short levels, each designed to take about 30–60 seconds. In each level, you operate two characters to mine diamonds and send them to the “little universe,” generating bricks on a three-column road. The goal is to get bricks to overlap the keys on the road before time runs out.

Work the mines

Mines are scattered across each level, and the numbers on them show how long they take to work. Each mine produces one diamond, matching the mine’s color, and then disappears. The white character moves quickly but works slowly; the black character moves slowly but works quickly. You can move only one character at a time, but either can keep working while you control the other.

Place the bricks

When a character sends a diamond to the “little universe,” a brick is generated immediately on the left-hand road. Red, green and purple diamonds produce vertical 1×2 bricks; yellow and blue diamonds produce horizontal 2×1 bricks. The road has three columns: red bricks occupy the first, green the second, purple the third, yellow the first and second, and blue the second and third. Bricks already on the road can support later bricks from below.

Plan your route

To solve each level, plan the order in which you send diamonds, since it determines the sequence of bricks placed on the road. You also need to assign the two characters to mines: distant mines are usually suited to the faster-moving character, while mines with longer work times are usually suited to the faster-working one.

Some levels include stars and black holes on the road. When a brick overlaps a star, the time limit increases by 5 seconds; bricks that overlap black holes are destroyed.