Glitches are errors in programming that cause some things to happen that really shouldn't happen. Exploits are certain things that can be abused in order to benefit the player. There can be good glitches and exploits and there can be bad glitches and exploits. Which is which is for you to decide. Use these at your own risk, we aren't liable for your messing up your game!
Rebinding Keys and Toggle Fire
This isn't exactly an "exploit" unless you think of the player exploiting the fact that they are on a PC, and not a console. In order to do the following you must have a program called AutoHotKey
Gatling Gun Exploit
This exploit also requires AutoHotKey, as well as you to have the first upgrade for Pod A. The basis behind the concept is the fact that whenever you press your fire key and have the first upgrade on Pod A, your pod will fire a single, powerful shot. So why not just press the fire key once every 0.08 seconds? To use this script, simply right click your desktop, click New > AutoHotKey Script, paste the code into the file, save it, and double click it to run! Note: the script is set up with [C] as the toggle key and [V] as the fire key; you will probably have to change a couple lines of code if your fire key is different, or you can just rebind your fire key to [V].
Code can be found here, along with a demonstration. Credit goes to Mashiro-chan!