Any tips on what I could do better?

I’ve been playing for around 6 years and still haven’t gotten past floor 4. I’ve been maining Marine and have been really conservative with any fun that isn’t the default pistol until floor 3. I don’t know, I guess I just haven’t gotten that talent yet lol.

I’m open for any suggestions that you may have, even telling me straight up that Marine isn’t the way to go lmao.