Luftrausers is a small, arcade-style game that packs a punch... if that's the sort of thing you're into.
The thing with Luftrausers is, not everyone's going to like it. I don't want to convince you that it's good, I want to tell you about it and let you make that decision. There is no story mode. There are no levels. It's one area, you fly around, you shoot as many things as you can, you die, repeat.
First off, let's talk about that. It's a game about flying around in an advanced German fighter plane machine thing and shooting up the enemies. Various airborne and seaborne war vehicles will try to shoot you down. And, sooner or later, they will succeed.
Your controls are a surprising part of what makes the game fun. You have your propulsion, which will move you forward. You also have right and left, which will turn you. Gravity is a thing here, it's not your typical bullet hell. But gravity is what allows you to perform cool aerial maneuvers. Fly directly up, stall your craft, then fall down past your enemies and blast upward at them. Laying back into the propulsion at the last minute to fly off to the side and dodge a battleship's bullets, of course.
Now, there are two things which add replayability, here. First, is the diversity in equipment. You begin the game with a basic machine gun, basic aircraft body, and basic propulsion system. As you go, you unlock four more of each, all of which completely change how your craft performs and operates. One type of propulsion lets you go underwater without taking damage. One weapon is a continuous laser beam which hinders your turn speed when in use. One body is a nuke which destroys almost anything around when you die. Which, actually, that last one's a ton more useful than it sounds.
Which brings me to the other thing. Missions. Each piece of equipment has a series of missions attached to it. Complete one, unlock the next. These are things like destroying so many of something, or blowing something up with a full combo going. Some are a little more outside the box, but there you go. Once you complete all of the normal missions, one final mission unlocks, which must be completed in SFMT mode, which is, for lack of a better label, hard mode. This unlocks the first time you destroy a blimp. And good luck with that. You're going to need it. And you're going to need it even more when you actually start SFMT mode.
Completing missions nets you skulls, and as you unlock enough or level up, you unlock new equipment. Once all of the equipment is unlocked, you unlock palettes. The basic palette is a sort of retro-beige affair. My favorite was the first one I unlocked, titled "Videodreaming", which is sort of indigo and pink, and honestly looks really cool. Most of the others I unlocked were eyesores, so there's a thing to be aware of.
That's honestly about all there is to it. You swoop and loop and blow stuff up and complete challenges and unlock things. I wouldn't expect to get TONS of time out of Luftrausers. But a few hours would be natural. If that all sounds appealing, then check it out.