Pros:
+Game looks really good. The levels use all sorts of filters like in those early shots to give them a cool artsy look. Some of the effects are great like the heat distortion in the desert. Animation is very good.
+Music is good.
+Game controls very nicely.
+Missions are nice and quick.
+Game is fun when you aren't dying horribly
+Lots of weapons/parts/other items to buy.
+Online is quick and easy to get working. I was in a 4 on 4 game in under 30 secs.
+You can take your 1p mech online
+When you beat certain missions you get "blueprints for cool mechs" but to make them you have to already have the parts or have enough money to make them.
Cons:
-Difficulty ramps up really fast and gets to the point where each stage is "I'm going to snap my ****ing controller in half".
-Because of this you're forced to keep replaying older levels for money to buy parts.
-You never get parts from beating levels so you have to BUY everything at HIGH prices.
-Parts are really expensive and you don't get much money per mission.
-You can't earn money in online for your 1p game.
-When you die (which happens over and over again) there is no "retry" option. So you have to go back to the mission screen, choose the mission, and load it again just to die 30 secs later after 1 min+ of loading. VERY annoying.
-With so many enemies at once, it's hard to lock onto a single one (aka if it's mission objective or laser that kills you in 1 hit)
-You can't stay locked onto enemies all that well (I hear this is an AC general flaw, not AC4 specific)
-Online is cute, but it's no Chromehounds because all it is, is short 1-5 min burts of action in a small arena. Shoot, dodge, shoot, shoot, game ends. No longterm goals, no interesting playtypes. Maybe it's fun to take your custom mech against a friend or two, but AC4 is a single player game with multiplayer tacked on.
-Did I mention you die A LOT?
Nice game, but as someone who hasn't played AC since AC1 the difficulty level is not-fun difficult by the 3rd chapter. I hear this is possibly because when the game started and you got to pick from ~10 different types of frames I picked the small and mobile one that was well-rounded in stats so my armor sucks. I may need to restart the game with a heavy mech and see if maybe it's not so goddamn annoyingly difficult. I actually wouldn't mind the difficulty since the stages are so short if I could just quickly retry...but I can't and seeing NOW LOADING for a min every 1-2 mins makes you really angry. From what I hear this is basically how AC is, so AC fans should be excited as its AC + high-speed + great graphics. People who never got into AC and it's "you gotta customize like crazy or you'll die!" gameplay, are probably just going to get pissed off. From Software needs to get ACE3 out ASAP on this engine. ACE is the perfect mech game for non-hardcore mech lovers as you don't customize much (just level up existing parts) and you just get lots of money each mission and use them to buy totally unique mechs. Chromehounds is for the slow sim-lovers, AC is for the fast sim-lovers, ACE is for everyone else. Hopefully that's their next mech game for summer/fall 2007.