The listing, Odd||Even [Steam Key] has ended.
Odd||Even is a math and logic based, integer placement puzzle game created by irritatingFLY studio.
Oddeven-game Features
powerful puzzle generator with natural interface
feature rich mathematical-software
full control given to users
sharp graphics
90 logical selected puzzles
full rights (once purchased you can use generated puzzles as you like, even for commercial use)
This game includes steam trading cards.
More info: http://store.steampowered.com/app/455940/