On many spinomental games you can choose the amount of lines you want to use, mostly from 10-100 lines. Have you noticed which one seems to pay the most? I always play with 100 lines but started to think if its even the best tactic?
Retro tapes might just be the easiest game to maxwin from all the slots that I know. Just do normal bonus buys and you'll hopefully get lucky, but I have already gotten a few and maybe bought like 50 bonuses.
Odds of winning is pretty much the same everywhere, you've just been unlucky not getting anything out yet. It is very difficult to win with free money so don't expect a lot of cashouts in general.