How is player count balanced in GSF? Is 2 player easier or harder then 6? is there a sweet spot? thanks.
I think the biggest difference is that with 6 players there's a lot more moving parts to keep track of. So it might be harder trying to order those things in your favore than with a 2 player game just because there's just less going on. But you have more eyes with 6. I'd say they feel similar but I have far less personal experience with 5-6 player games as I do with 2-4
Is there anything like the H mechanic?
No, with more people you start off with more opp ships, and the fleet limit is higher.
In my experience two player games go one of two ways. Either you go on extreme offense and cut down the opposition, resulting in a tidy game no more than half an hour to forty-five minutes or the opposition gets the chance to build up some and the players do their best to cooperate and catch up with the enemy ships. 3-4 was the most challenging for my group, as it increased the number of starting ships while we didn't quite have the numbers to wipe them out as swiftly as with two players (those 1-2 extra card flips they get can really change up the game). 5-6 makes the game longer, but you generally have a bit more control. There are a lot of bookkeeping elements in the higher player games, but that's where you can get some really impressive co-operative dynamics and combos.
I think the game shines when you have a large group of players, but the dynamics change in a refreshing way depending on how many you have. 2 is like a small shootout, 3-4 is a small band of heroes against medium to large odds, and 5-6 jumps up to a full-on army versus a small squad of determined pilots out to save the galaxy.
The challenge is relatively consistent, but the feel of the game really shifts with player quantity, if that makes sense.