Researchers agree: playing logic puzzles requires your brain. Exactly what's required of it, they can't seem to agree, but it's the general consensus that the net effect is positive. Enter Strimko, a sudoku-like game of logic that involves placing numbers on a grid. Instead of a dry, angular box, however, you get to work with number chains that snake their way around the grid, adding a nice, flavorful twist to the familiar concept.

Logica is a color and number based puzzler from Candystand. The goal is to follow the instructions each level provides, and sometimes the point of the puzzle is in figuring out what those instructions are. There are three tiers of difficulty with ten levels each, plus a useful five level tutorial. The theme is good, the concept well-conceived and usually the puzzles are clever and a solid application of the concept.

Zerosum is an intense variation on match-3 puzzles, with strict policies on winning and losing but vast opportunities for strategy. Easy to learn, hard to master. Make matches by adding adjacent numbers together, but make sure you don't run out of digits to replace them! It's brain candy, once you get into it, like defusing a bomb constructed by an six-year-old arch-villain.