I can appreciate having to tap buttons quickly... in games like Flying Shark and Plus Alpha... you can have a steady rate of fire from your finger, but when you want to take out the hardier enemies, you gotta test your speed tapping skills. Some games that don't give autofire off the bat make things a little too difficult without it, at times, but others seem to keep the no-autofire mantra in mind. That classic gameplay is pretty cool
Then there's mushi where you tap as fast as possible for C fire skyrocketing
I've thought about using rapidfire as being unfair, but I think you have to gauge the difficulty at the same time. Gradius games for example, they are kind of wild to play without autofire, but on the other hand, if you're not using autofire, the lazer powerup should be preferred because it allows you to hold down the button for continuous shot. I guess that mindset was in Japanese players on cabinets without autofire... I'm not sure how widespread autofire circuits were / are. That being said, of course I play Gradius games with autofire, but having missle and shot on seperate buttons is essential for high level play
