Many playground games will allow players unlimited time or turns to achieve the game objectives. Classics like risk or diplomacy have open-ended playground style structure allowing great freedom (and sometimes very lengthy games).
Many Euro Style games have adopted a limited turn length for the game, allowing a finite period in which to achieve objectives for strive for victory. In a victory point based game like Project KQ, I have opted to explore a limited number of turns for the game. This combined with the dynamic nature of the board, should add weight to the decisions players make toward objectives, while at the same time giving a very clear idea of over-all play time for the game itself.
In my gaming group, sometimes play-time is about as important as fun. We often like to crank out 2 or 3 games on a friday evening, giving multiple opportunities for a 'win' and ensuring that no one gets 'the screw' for the entire evening. With player elimination/unlimited playground games like Diplomacy and Risk mentioned above, this is not possible.
Attached is a late-prototype of the turn tracker mat for Project KQ. It limits the game, and provides an opportunity to get rules onto the table so that players do not have to continue referencing the rulebook or cheat sheets during game play.
For preplanned expansions/scenarios for the game, I have designed a couple of turn-track overlays that change some of the dynamics of the game to suit the specific objectives outlined in the expansion/scenario. I am also working on a turn-track overlay that includes a 100% cooperative play game (no traitors) that could appeal to a particular demographic of euro-style board gamers.
Note: I'm toying with the notion of moving Castle Improvement rules off the player mat, onto the Turn Mat, leaving only built/unbuilt indicators on the player mat. This choice would be for design cleanliness, and a better UX or IA for the game. (UX = User Experience; IA = Information Architecture).