Know what the mouse actually controls
Sky Hunter 3D says to steer the aircraft with the mouse and states that it fires automatically when it sees an enemy. That removes a manual firing input from the listed control scheme. Focus first on how steering changes the aircraft's position and what the game counts as seeing an opponent. The wording does not specify a targeting cone, lock-on range, or exact aiming model.
Avoid an endless chase of your own
The description says enemy aircraft follow the player. That makes the space your route creates worth watching. A turn that brings an enemy into view may also alter where the pursuing group gathers. Compare the immediate firing opportunity with the room remaining for the next steering decision. This is a route-planning question, not a claim that a particular circle or turn pattern will defeat every opponent.
Reassess when the field grows
The supplier says enemy numbers increase with level and advertises a collection of aircraft. It does not provide individual aircraft statistics or a dependable unlock sequence. As more opponents appear, return to the same practical questions: which are visible to automatic fire, and where can you steer next? A useful attempt can improve your understanding of those relationships even before it advances to a new aircraft or level.