I have to admit, that this game is more than I can handle alone right now. It's been a long time since I made the last update. I started it over from (almost) scratch at least 2 times, I also wanted to add online multiplayer, but it's still beyond my knowledge.
I don't know if I ever will continue this project,* but if I do, that won't be in the near future. For now, I removed the game files from the page, because I plan to make a last update for it.
Overall, I have no regrets, I still learned a lot, and got a lot of feedback, so thanks for everyone who helped in any way! :)
*However, I quite like the characters and weapons, so it might be possibble, that they will return in a totally different kind of game... ;)