Loop Invader

My entry for the Ludum Dare #47 Compo

There are invaders hiding among your data! Use your observation skills and code blocks to track them down and hit 'em with your ZAPPER!

PERFORMANCE ISSUES: if you are experiencing lag, please download the native version for your operating system. The HTML5 version seems to struggle a bit.

How to play (TL;DR version)

Each level has a bunch of balls in a grid. One or more of those balls are an "invader". You need to figure out which balls are invaders, and then zap them with your zapper! (spacebar)

Hints:

• When an invader touches a regular ball, that ball's number will go up exactly 1 second later, but the invader's number will never change.

• Trying to spot the invaders with your eyes alone is not going to be easy because there is usually too much going on.

• Create while blocks to trap balls, and create if blocks to create barriers. This enables you to control the movement of the balls, and makes it easier to spot the invader(s)

• An easy trick to narrow the search for the invader is to collect each number into a separate while block (easier said than done!). If you manage to do this, you'll know what the invader's number is by looking at the while block that is leaking data.

• If you capture all of the data that leaks from a while loop, then eventually, the while block will contain nothing but the invader(s)!