What is the overall difficulty to get all of the trophies?
Depends on your patience and ability with twin stick shooters. It's not overly difficult and if you follow the patterns you can do it fairly easily but a few of the later zones are going to make you play them a few times to get them down.
"I do not agree with a word you say, but I'll defend to the death your right to say it."- Voltaire
The First Wrestling Platinum Grand Slam Winner on PS3Trophies.com