Cool game, but with some flaws. Nothing is perfect anyway, so its still a great stuff.
First off, the mission gets a little repetitive. Most of the mission objective was either destroy all targets or prevent your mothership from getting destroyed. Secondly, even though the controls is easy and simple, it does gets a little messed up in a space fight, for example you don't know which way is up and which is down... sure those things aren't important in space but it really gives you the hard time trying to fly to a certain point in space, and sometimes you end up having trouble like trying to fly vertically and you find yourself turning horizontally in space (look at the minimap and you'll see what I mean). A big problem to me is that sometimes the targeting system furthers the problem, like your trying to reach a target behind a bunch of grunts, then just when you thought your going to lock-on to you target, you lock-on some grunts flying around you and therefore messes up your already messy space orientation.
Nevertheless, A.C.E. 3 is still a great game. There are some new mechs in this game including Gundam from SEED series and Eureka 7 and more, and Gundam W fans gets a new view of Wing Zero. Certain feature of the game is fun, and combination attacks get really flashy and cool when you select the correct combo. I enjoyed spending my time unlocking and upgrading mechs. Mecha fans will find themselves stuck with this game for quite some time.