Thank you very much!
I recently think more about making it less pixelated (the whole game), but yet oldschool like. Maybe I could use as a placeholders sprites from doom / brutal doom (or some other custom weapons used in doom series), same for enemies, props etc.
But I need to make a story for the whole thing first, and that's the part I'm a little bit stuck with right now. Maybe something like wolfenstein 3d stuff (escaping from prison) + military experiments (like zombies etc).
Greets!