Having finished de_kobbl itself, and having promised to make a fun version, I decided to work on it a little bit. So far, I added the basement part, and I've been working on the mortar, which should be in the basement.
It's pretty early and it needs tweaks, as well as being able to actually send the mortar at one selected location. For now, it just sends the same bomb at the same place, regardless of any one of the 3 targets on the panel.