HeXeR

HeXeR is a hacker-themed mathematics puzzle game. The goal of HeXeR is to achieve a specified sequence of hexadecimal numbers/letters by using mathematical operations that fall from the top of the screen.

At your disposal are several powerups: deleters, which delete undesirable operations, duplicators, which allow you to duplicate numbers, swappers, which allow you to swap adjascent numbers and scramblers, which reassign a random value to a number. 

There are 4 levels with 4 speed settings, each of which are unlocked by earning 'bits' by beating levels. Higher levels and higher speeds result in higher rewards, but are also more challenging.