Killer Station is another space shooter, but it reminds me of something more specific. Maybe an element of Phoenix or Gorf? The idea is you have a big barrier around your enemies that you have to shoot through or between in order to have a path to hit the targets. But it's harder than that, because even if you open up a hole in the barrier, the barrier is constantly moving and regenerating! But you also have a (smaller, flimsier) barrier of your own, so it's not as lopsided as it might seem. But all the barriers does make it a longer game.