I've been very surprised at how little attention this game gets in TA Forums, shmups are usually very popular here. I know, it's free-to-play, but you don't need every plane to go far in the game. If you're playing daily and completing missions you'll get tons of free gems, gold, parts, etc. It's been a favorite of mine for a while now!
I agree that shmups are liked in TA forums but I think the problem with this game is obvious. Developers are greedy and not creative at all. You kill the same ships, same formations, same patterns for 180 levels which are almost same in order to play the same level with a stronger ship. Besides that, developers are only focusing on monetization, not experience.