The GM’s Turn / Player’s Turn is not a hindrance, or even much of a factor other than it structures the game for the GM’s notes. I didn’t even mention the concept to my players, it just sort of occurred naturally – “you’ve accomplished your mission, and have some time for R&R in Lockhaven… remember those checks you’ve been collecting?” If your players are wary of losing the freedom of open-ended RPGs, it’s really easy to skip the rule without losing anything.

Combats were fun and furious – my biggest problem with running D20 is how long high-level fights take to complete a single turn, how long low-level fights take to get a hit, how long it takes to get from one action scene to the next, etc etc – but in this system my party was able to gang up on a snake, chase down a fleeing NPC, have an inter-party argument, and fight the ravages of hunger on the road without any long pauses for bookkeeping or looking up obscure starvation / extreme weather rules.

I also noticed normally silent players chime in with memorable RP – like somebody flipped a light switch in their head, and suddenly they were The Thespian. I noticed a similar effect with other systems that quantify your character’s personality, but the simplicity if MG’s Beliefs / Goals / Instincts is a lot more inviting than most because of the focus on short-term actions.

The mission structure? Just like the GM’s turn / Player’s turn, can more-or-less be skipped. Maybe it’s my own fast-and-loose GM style, but the adaptable mechanics of conflicts and the ease of the skill system makes it easy to run the game fast and furious. If we didn’t spend half of the session goofing around (it happens) we could have easily completed two more missions, or a larger plot. Point is, there’s more to do once you run one or two by-the-book missions to learn how it works.

Simple version: if you’re worried about the game’s apparent structure, don’t be. Like any good system, Mouse Guard is as flexible as the GM running it.