Barriers: Player recruiting/retention

Barriers to return / replay...
Availability of other players, lack of connection with the theme art or mechanics, strategy exploit that unbalances game, unfamiliar game group with many house rules for said game, mood

Barriers to trying / demo...
Current playtesters don't look happy/enaged, person demonstrating the game is holding the rulebook, not appealing (either game type or overall theme), quality of finished product is not up to expectations (i.e. I expect PnP games to be printed on paper with uneven cuts; I expect Mayfair games to be printed on sturdy cardstock, etc.), obvious attempt to slap a popular theme on a poor game mechanic

Don't wanna play again if:
1. Only one path to victory - same strategy every time
2. Too random - "oh, you rolled a 6 you are out of the game"
3. Too not-random - the same player who knows the game win every time.
4. Locked Strategies - if you start of with one strategy but then have to change (because too many other players compete within that strategy or events change the playingfield) this should be possible and still lead to victory. The first few rounds should not lock your strategy for the rest of the game.
5. Too little player interaction - some of the traditional deck builders suffers from this in my mind.
6. Too rule-intense - not fun to have to pick up the rulebook all the time
7. Too much downtime - not fun to sit around waiting for other players to act.
8. Boring theme - but this may be overcome by good game mechanics

Cheers!

The other posts address the game itself, but I think personality conflicts, busy lives, and differing ideas of what is fun play a major factor into how well a group holds together. We've had a small steady core in my gaming group but it seems to have been taken over by "collectors": people who seem to enjoy owning, perhaps even over playing. Most conversations on my BGG guild "clearwater boardgamers" revolve around buying something new.

I think there is a great degree of narrow-mindedness in a collector group against things that aren't a finished product. Play-testing is something I can ask one other person in my group to participate in every time, and everyone else I try to give it in small doses.

For components, I think setup times can be prohibitive, but that's usually a result of the complexity of setup rather than the number of pieces, per say. Whats most important is that players easily understand what they need out of the box and where it goes.

Player elimination is a huge negative for me. I usually play with a group of 4-6 friends, and it's never fun to be eliminated and sit around and you wait for everyone else to finish. It's never fun when someone throws in the towel on the second turn because they've been statistically eliminated, so we tend to play games which allow as many people as possible have a relatively competitive chance to win for as much of the playtime as possible.

I typically like games where chance is an equalizer, but not a determinant. I want to feel like my actions and strategy had the largest impact on the outcome of the game while the game allowed people of different skill levels to be competitive. Maybe the die roll doesn't go my way in the end, but I want to feel like my decisions influenced the odds of that roll work in my favor.

Interestingly, I find that some games which push the boundary between luck-determined and strategy-determined can be incredibly addicting. If I feel like I had a great strategy and would have won if things had gone just a little bit differently, I usually want to play it again so I can prove my strategy (or a variation of it) is viable. Sure, it always sucks to lose that way, but I'm obsessed with trying to figure out how to tweak my strategy afterwards, I'm hooked. Usually, you think of people replaying games because of their positive experience, but sometimes the right kind of frustration can be a powerful way to get people immersed in your game. The best thing a game can do is make me incessantly ask, "What's the best path to victory?" and leave me with many intriguing possibilities but no definitive answers.

I like intense competition (both direct and indirect), but "mean" games usually suck (in my opinion). When the competition is so aggressive and direct that it becomes abrasive and personal, it usually stops being fun (and this can be a tone/theme issue as much as a mechanics one). More fundamentally, games where players compete to see who is the most brutal and ruthlessness rather than who has the most wit and creativity end up being a dull and predictable race to the bottom.