I've played Aka to Blue pretty much every day since release day and am currently trying to get past the last phase of the chapter 5 boss.
Playing on a samsung galaxy s7 the controls are supertight but the screensize of a smartphone during bossbattles can be an additional challenge. I'm very sure the game was not only tailored for touch controls but also for a screen that is bigger than a smartphone, a 10 inch tablet being probably the perfect device for this current version.
The blue arrow that let's you aim your bombs can only be found on the second ship. Choose the red one and you don't have to worry about aiming 'cause it always fires straight up. The red one is definitely a better option for beginners with its wide shot and simplyfied bombing.
If you want to play effectively you HAVE to learn when to bomb. In Aka to Blue bombs are not screenclearing smartbombs but more like the katanas in Akai Katana's Slash Mode. When powered up they eat through literally everything while repowering up the bomb meter.
If you know when to bomb it can not only be a life saver but also a very satisfying and powerful mechanic.
Imo everybody who enjoyes Akai's Slash mode should definitely try Aka's aggresive approach to bombing. You never just dodge shit here...rather you dodge until you reach the best point to bomb...rinse and repeat. I really like it
I don't mean to step on someone's toes but saying Aka to Blue doesn't feel like a cave game is pretty silly considering Hiroyuki Kimura - head of Tanoshimasu - was heavily involved in the creation of Akai Katana Shin, Dodonpachi Saidaioujou and Dodonpachi Maximum. Mechanically, it is most definitely inspired by those three games.
Although imho Bullet Hell Monday is a better game with more content and variation I really hope Tanoshimasu don't give up after this one. Talented team and a great game. Highly recommended.