Luftrausers is a very fast arcade-style shoot 'em up. And that basically describes it, because there's no plot, no stages and barely any progression. Is an extremely bare bones simplified game with not a lot of variety in which the sole driving force is smashing hi-scores.
I cannot blame this game for not clicking with me, since what it's trying to do is very much not my cup of tea. I like a game in which there's some consequence to my actions, be it by making choices that dramatically affect the plot, or just by advancing through different stages with different enemies or things to do. Luftrausers it's pretty much the same game from the first time you boot it up to the moment you decide that you had enough.
That said, all that means that for people who do love a fast-paced shooter, there's no excess fat to cut around. You get what you want and also done with expert tuning. Because what this game does do, it does well. The planes are extremely nimble, enabling the player to move with ease among the bullet hell that ensues with more than a handful of enemies are flying around. In a split second you can turn to shoot enemies on your tail, then stall over a boat to sink it and quickly accelerate out of the way of incoming bullets.
Everything is fast and frenetic but not chaotic; it needs strategy and skill. Since you only recover health when you are not shooting you cannot just keep your finger in the the fire button and hope to kill everything. You can dodge enemy fire and recover, but if you spend too much time without exploding something, your multiplier goes to zero. Battleships have a clear cycle of shooting-reloading-aiming that you must understand and exploit if you want to sink them.
When you inevitably explode and die, you can start over literally with the push of a button; no loading screens or death animations between you and another round of fast shooting.
At first you start with a standard plane but you quickly begin to unlock new bodies, engines and weapons from which to choose from. There is some variety and the different combinations (each with it's own name, btw) play very different. Of course, each has it's own strengths and weaknesses and also their own set of "missions" (which more accurately described as "achievements"). You can be a slow and heavy bullet propelled tank ("The Slug") or a very fast blade that kills by ramming into things and shooting a massive blast of energy ("The Staff Pick"). If you are in the mood of sinking every boat you encounter, then you might want to pick the melee body with the underwater engine ("Shipwreck"), but if you are planning a suicide mission you should really pick the nuke body, which explodes upon death with a laser weapon and a very fast engine ("Batman"). Or, hey, if you prefer to flow with the waves of destiny, select the "random" option and be surprised! The choices are endless (factually incorrect, there are 6^3 choices) and well balanced.
The thing is, after about 4 hours I had already unlocked everything (save for some "clasified" parts) and the sense of progress was all dependent on some numbers I got at the end of each run. I'm sure that for some people, beating your hi-score is a real driver, but not for me.
Luftrausers has a very limited set of skills that are not my taste, but they are sharp and honed in. If you like this genre, you should play it.