Well my 5cents are in:
My "game group" revolves around a (still not but getting there) non-gamer wife with short to none attention spam for rule explanation, a 5yrs (almost 6) daughter still learning how to gracefully lose and a 2yrs (almost 3) toddler who just like to hang around the table.
While the topics have no specific order the buy/not-buy will be defined on how they interact with each other:
Theme - Personally I'm not much into horror so even if I had a more mature "game group" anything with zombies, cthulhu or
monsterish stuff would have to score high on the other topics to make the cut.
I somewhat avoid to double the themes on games but buying a game just because it as a "friendly", "new" or "exquisite" theme doesn't always work.
Art work - Friendly art work will always create a proximity to the game especially when you play with kids. Some games are also obliged by its own theme to have an above par art work so if they don't they will probably don't make the cut.
Game weight/complexity/fun factor - Any game that takes too much time to learn, explain or where I can't play while teaching the base rules usually won't get any table time, anything with hidden written stuff is also, as you can figure, difficult to put on the table.
If the fun factor is high it can override the weightiness/complexity since it will drive the desire to keep learning/playing it.
Play Time - We usually play on evening, after dinner, when the kids start to slow down or in order for them to slow down but if it takes too long they will get sleepy and start screwing around.
Again theme, art work, fun factor can boost their attention for a few more minutes but I would say that anything beyond 30m to 45m is already pushing it.
Cost - Again a question of balance, if the game is to expensive but I'm sure all the other attributes are spot on I might go the extra pound on it but if a see that it won't get much table time or is to much complex for my "game group" I wont spend a dime.
Heldentaufe - Teens fighting monsters on dungeons... theme might sound off but completely nailed it on the art work and fun factor, kids love it.
Martians - Story of Civilization - Bought it mainly on the space/mars theme and the art work and scenario mechanic looked great. It's so f$$#$ complex that I want to sell it.
Dream Home and "Slide Blast" - Friendly art work, not that complex, fun, simple theme. Bought are family favorites.
The 7th Continent - Way too heavy for the crowd and I knew I would want to play it solo, crazy long play time, impeccable art work, slighlty on the Lovecraft theme, expensive as s$%&. Overall impression....
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