This is an obscure bullet hell shmup from a Japanese developer known as Jakiganic Systems, released for free in 2013 for android phones. All of the sprites are weird as fuck, the art and fonts are stolen and the UI is shit. The game was removed from the Google Play Store in 2018 for unknown reasons.
Despite the fact that it looks like trash, The game has an absurdly high skill ceiling, and a soundtrack that is unexpectedly good. The game never ran ads, and the game was always completely free.
The game is a time-attack shmup that features 31 bosses, with 4 difficulties each. The assortment of bullet patterns ranges from plain and simple, to patterns which are exceptionally hard to navigate. many boss patterns are also stolen from other bosses from classic arcade shmups. Boss 14 is Black Heart from Battle Garegga, bosses 8 and 18 are Hibachi from DoDonPachi and DoDonPachi Daioujou, respectively. Boss 28 is Evaccaneer DOOM from Ketsui.
The ship is controlled by dragging your finger around on the screen, and the game will let you increase the control sensitivity up to 300%. This is a very important tool which will help you later. Your ship will always fire a 5-way wide shot, except for in one level. The game limits the amount of your shots that can be on the screen, so point-blanking bosses will increase your fire rate, and do more damage.
Another important mechanic is the "force field". You do not start the level with one, but it recharges about every 12 and a half seconds. When you press 2 fingers on the screen, or bind the force field to a volume button, you will generate a force field at the position of your ship which blocks all enemy projectiles and lasts for about 2 seconds. If you trigger the force field while you are moving, the force field will travel at the same momentum in the same direction you were moving. When you manage to land the force field on the hitbox of a boss, it will do an absolutely absurd amount of damage.
The game has an exploit where you can effectively teleport anywhere you want instantly, provided there is no projectiles in the line between point a to point b. While holding a finger down, press another one on the screen where you would like to go, and let go of your first finger after. This is affected by your touch sensitivity, and you're likely to overshoot. Even though its an exploit, it is extremely difficult to go where you want to go consistently, however if you know what you are doing, it can make a great difference in your score.
This combination of mechanics constructs one of the most unique shmups i have ever played. The game had leaderboards at one point, complete with recorded replays which were uploaded with scores on the leaderboards. These replays were about as ridiculous as you can imagine, even if many were likely tool-assisted.
I've had this shit installed on every phone I have bought and I still find myself improving at it when I boot the game up every once in a while. This fucking thing is the only mobile shmup i have played that turns the shittiness of playing a shmup with touchscreen controls into an actual game mechanic that makes sense and is fun to play. The music is fucking killer despite it being made for a shitty little phone game.