I think the game looks intimidating at first, but the core box does a good job at guiding you through the rules. It is certainly a game where I took learning it seriously (not reading the rules 20’ before and hoping to wing it :) ). But it actually plays in a very predictable way. It’s easy to grok how a turn goes. So, after a couple of turns, you and your GF should feel pretty confident that you understand the flow. The harder part is doing well against the mysterious forces at work. :)
As for how I learned, I watched this video to get the quick start rules:
I think I also watched this one to see someone setting up and playing. But the quick rules would cover the same grounds:
So you would have watched 25’+ of video before playing. But, really, all your GF will need are the player reference cards. They remind the players of the sequence of a turn (just follow along and do what it says) and what actions you can take on your turn on the other side.
As you go through the set up for your chosen investigator (may I recommend Wendy for your GF? She is very cool), you can tell her about the the cards you are pulling (this is an asset. It will be on the table and let you take advantage of its effect. This is a skill card, that will help you when you look for clues / fight a monster / run away / … depending on the card. And so on). Tell her what the cardboard tokens on the table mean. But leave skill checks explanations for when they happen (look at your investigator skill value, use assets or skill cards, draw a token and hope for the best :) ). Keep the rules overhead low.
And then you can start playing the first couple of turns with your hand on the table. That way, you can discuss what you are doing on your turn with her. Same for her turn. Once you feel confident, you can pick the cards back up!
In effect, all you really need is one person with a relatively good idea of the card types and structure of the turn. And the other can follow the prompts and learn as they go. I never looked at the full reference manual before playing. We simply would open it and look a special term we didn’t know when it came up. Worked very well that way.
If you have some time before you play, I might recommend watching this video as well. For your own peace of mind that you understand how interactions with the monsters will work. But, again, it’s more for you to have the confidence to put the monster in the right place when it is drawn. You can also look up the same things in the reference guide as you play.
The video above helped me keep the game flowing more smoothly when combat occurred though.
The set-up is a bit of a bear. But it comes from the fact that each scenario needs to be set up differently. They have their own combination of scenario, monster and treachery cards. They might have a different distribution of tokens to put in the draw bag. So there is no standard set up beyond: characters shuffle their deck and will draw 5 cards and 3(?) resources at the start.
I think the game is worth it though. It’s tense. It’s thematic. My wife and I had a good giggle at how badly we have been doing in the first campaign. It’s part and parcel for the Mythos games. And part of the fun for us.
I hope you 2 enjoy it!
PS: Do you play with the English version? If you do, enjoy the game and decide to get The Dunwich Legacy to play more stories, let me know. I have a duplicate of the first mythos pack used after the core Dunwich box (the pack is called Night at the museum). I’m not using it and would be happy to send it to you to save you from having to source it.