This took way longer than anticipated. I'm not finished yet, but the wall blasters are well underway.

Wall blasters will periodically shoot a bullet in the direction they're facing. That's about it. 
It sounds simple, but shooting a bullet, bullet impact and integrating wall blasters in the editor really took a lot of time.
The wall blaster paved the way for a lot of future stuff in different ways. For example, I didn't have any code that restricts placement in the editor. Wall blasters need to be mounted on a tile, which means they can't be placed in mid air. 
I now built a generic way of checking if a spot adheres to specific rules.

Checking if a collision happened with a specific type of object (a bullet for example) was also not possible, so I also built a generic solution for that as well.

I can't even remember all the other needed stuff, this all took too long.

In the top of this post you can see how it looks now! Don't pay attention to the ugly bullet.

See ya!