Several Changes. Some good, some bad
First thing I noticed was the change in single player difficulty. In BF1 I played Conquest on hard and could win without ever dying once. Im BF2 on normal I've actually lost some maps because of the fact when there your side is down to 1, you better believe you arent the only one alive. This jump in difficulty is a definite plus.
I love how they changed the strength of the vechiles so that while you can kill infantry, its not spawn camping strength. You can kill them pretty quickly with your rockets but the blasters just annoy me overheat so fast and barely kill anything. This is a plus for me because I love playing as infantry sniping away at anything that moves. Unlike what many say they did not gimp snipers, they just changed em. You dont get to go prone but getting headshots is immensely easier now. The auto turret is cool cause you just deploy it to cover your back while your in your scope. I'll miss the orbital strikes but this seems to be a fair trade off considering how they changed it so that its not super easy for anyone to be gods of war killing anything that moves.
The new control scheme I'd rate as a plus. You can roll forward HURRAY. Sprinting around, and the world rejoices. You can actually roll in a spacecraft. The only problem I have is with the annoying target lock, its okay in space. But when I press strafe in infantry I want to go right, not a circular path. You might believe that you can do without this tracking but in some lvls it is almost impossible to see stuff w/o it. But the positives definately outweigh the negatives here.
Heroes are fun, but by no means are they invincible like in the first. The most annoying part in single player of being a hero is capturing posts, just watching your 'health' tick away. It would've been better if you got a health spike whenever you took a spot cause I find myself refraining from capturing spots because I know I'll lose my hero waiting to take over.
The space thing is iffy. I like it, but only in sparse amounts. Playing galatic conquest I got really tired of space battles cause even tho they were in different locations they were essentially the same thing. Pilot - Get on enemy ship blow up shield generator, blow up stuff inside. Grab enemy bomber and just finish off vital systems. Even when I just went stupid and goofed off this is extremely hard to lose in single player. Fun in multiplayer split screen, but I'd imagine it'd get old online not seeing your opponents reactions face to face.
Overall I'd say this game is alot more fun than the first, but I'll deeply miss my stress relief sessions of watching the flying ewoks in the safety of my AT-ST.