Catch the falling numbers and place them in the grid to solve each level. Try to minimize intrusions (wrong numbers); they alert the system to your presence.
As you get further into the system, you'll encounter more challenges (faster numbers, even/odd and reverse numbers) and hazards (/tmp numbers, rotating keys, and viruses).
Can you crack the code?
Written by J. Kira Hamilton.
Music by Tom Smith.
Please send bug reports to <firstname.lastname@example.org>