I have a FISHTALES and i would never part with it. I read your post with interest, and what you have descibed, i would say is "simply pinball at its best". The game designers did a excellent job on this machine for sure. Easy one minute, reasonable the next, then friggin hard with quick drains. Waxed up well, she will play hard n fast.
I even fully redecalled mine at great cost cause its a keeper for sure. Personally, i dont adjust things on any pinball to make it easier, i try to leave it just like it came from the factory if possible. I like the fact that when u play most games, you walk away saying "I will get u next time bastard". I think that is what Pinball is really all about.
When i first saw a FISHTALES, i said to myself, "only fisherman would buy a machine like that". After hearing from most that it was a great title, i watched the factory promo video and bought one. What you are describing in your post is normal. The pinball machine is doing its job well and keeping u coming back for more fun and punishment.
promo videos can help with some gameplay n shots etc. a fun video worth a watch. very 90's.