HAWK vs Sky Force Anniversary
HAWK
HAWK is a rather new, mobile arcade shooter game that pays homage to the glorious arcade days of the 90s where games like Strikers 1945, Raiden DX and even Galaga dominated arcade centers worldwide. Featuring an exciting and challenging gameplay, you'll pilot your aircraft through various airspace in an effort to defeat the overwhemling armada of the tyrannical Autocrats as well as the massive robots that they build. As you progress, you'll get to reoutfit your aircraft with a variety of upgrades for your guns, shields and boosters in order to be able to take on tougher enemies, but unfortunately, the game can be quite grindy since you'll need plenty of resources just to get an upgrade. That's not even including the upgrades you need for your BroBots - the two AI-controlled companion aircrafts that will help you in battle. That said, HAWK also has over 130 levels of outstanding arcade shooter experience that comes in three difficulty levels.As surprising as this may sound, there isn't as many great arcade shooters on mobile than you'd expect. However, HAWK is definitely one of the better ones. It may be grindy due to its freemium element, but gameplay-wise, the game can sate your arcade-style shooter fix for sure.
Sky Force Anniversary
Sky Force Anniversary brings Sky Force to platforms other than Android and iOS, namely PC and consoles, allowing even more players to enjoy its exhilarating arcade shooting action. It is basically similar to Sky Force 2014 on mobile and features everything you'd expect to find in the latter, including challenging enemies and bosses, large number of missions, weekly PvP tourneys, an in-depth airplane upgrade system along with a wide variety of planes to fly as and weapons to blast enemies into smithereens. In this version, you can also play the game cooperatively with a friend through the game's local multiplayer option.Oddly enough, despite its similarities to Sky Force 2014, Sky Force Anniversary is available on Android as well. Unfortunately, I'm pretty sure the game doesn't support cross-platform cooperative gameplay so you can't exactly play with your friend cooperatively if he is on the PC and you on your phone.
Sky Force Anniversary is the best (and only) version of Sky Force that you can get for Nintendo Wii, PlayStation (3, 4 and Vita), and Xbox Live, but if you want to play the game on your mobile, you can get either the Anniversary version (Android only) or the 2014 version.