Watched trailer so many times again and again, with earphones, and highest volume!!!!!! @.@ The trailer is also sooo masterfully presented. You get like a nice text graphic, and you're like "oh this is gonna be good!" And then WHOOOSH!!!!!!!!!!!!!!! Like a rollercoaster instantly diving trillions of feet downward, you desperately try to hang on!!!!!!!!!!!!! @____@ And it makes sharp turns left and right and sideways and spirals without warning!!!!!! @____________@ And then the rollercoaster skyrockets upwards lightyears upward as glimpses of the world flash before you!!!! @.@!!!!!!!
The first one is great (in my opinion), wonderful WONDERFUL characters, lovely interaction and three dimensional personalities, customizable battle system (combos, summons, etc.), unique character skills and cinematic ultimate attacks (with extended ultimates for boss fights), dungeons aren't open but they often have more paths to explore than one. While the healing system isn't common, it's easy to understand and use to your advantage as you get more points and healing skills. Interesting deeper story and twists aside from the parody elements, and much more! MK2 looks to advance and improve the foundations the original started!

The 'sequel' is like a new version/markII so people don't need to play the first to understand this story (but it could help you appreciate the returning characters much more!) The first one sold well in both Japan and U.S. regions, so localization could be in the plans (the first one has top quality english VAs, by the way, fans admit they fit better than the Japan VAs!) !
「超次元ゲイム ネプテューヌ MkII」Chou Jigen Game: Neptune MkII - PV01