(1) Each of the dozen-odd enemies has a specific attack pattern — which gives you a very specific way to defeat them. Figure out these counterattacks and stick with them. For example:

• Tachrok ballistic missiles — When the curtain of missiles drops, don’t try to destroy them all; focus on destroying one or two Tachroks (firing your weapons straight up or at a slight diagonal), giving you a safe spot where you can sit while the rest of the missiles land harmlessly around you.

• Havanski atomic bomber — If one of its bombs hits the ground, you die immediately, so you need to demolish the bomber and its payload simultaneously. The best approach: When a Havanski appears, immediately move directly under it and then follow it across the screen, firing straight upward. That way, any of your weapons that miss the bombs hit the bomber, bringing a quick death to all of them.

• Romanov attack satellite — The Romanov’s lasers are unstoppable, so focus on the satellites the second they appear, hopefully vanquishing them before they can fire. Standing to one side while attacking with your laser (as shown above) is best. Make sure you’re not backed into a corner: if need be, cross under the satellite before it fires.

• Shovak bulldozer — This heavily armored ground vehicle usually attacks alongside satellites and cruise missiles — and focusing solely on one of these enemies will get you killed by another. Four to five laser blasts will destroy a Shovak, so when it rolls toward you, shoot it once or twice; back away from it while firing at airborne attackers; and then quickly switch back to the Shovak and finish it with two or three more shots.

• Fovraski cruise missile — Knowing that these missiles make a right-angle dive once they’re directly above you, position yourself so that you can roll to where you want to be once they begin diving (as shown above). For instance, if you’re fighting both a Shovak and a Fovraski, position yourself so the Fovraski will dive near the Shovak, giving you room to then back away from the bulldozer instead of toward the bulldozer.

(2) Which weapons should you buy first? For protection, the defense orbs and flak cannon provide shielding from enemy armaments; we maxed out the orbs first, but both weapons are solid. For offense, prioritize homing missiles (which seek out onscreen opponents) and the laser (which gives you a devastating, surgically accurate strike, especially once it’s maxed out).

(3) Against bosses, nukes are vital, so save these weapons until the end of each level. However, since you lose all your nukes each time you die, don’t hesitate to deploy one mid-level if you have several and you’re about to perish.