Early levels: the far edges are reasonably safe while aliens enter the screen. But sub-boss aliens specialize in lateral, corner-targeted, track-shooting rounds. Keep moving to break their prediction algorithm.

Double Shot is probably your most practical workhorse: fast, stackable with Extra Bullet, easy to aim. Triple/Quad are better in Warp Malfunction levels. Fireballs are the best bang for the buck among shop-only weapons. Auto-Fire on a maxed weapon turns you into a death machine.

Gems from Gem Bombs are worth serious points. Rank Markers you already own still give points. Never skip the Meteor Storm — you literally cannot die. Buy Extra Time from the shop: at higher levels, accumulated Extra Time can give you 15 minutes in Memory Station worth millions of points with a ×5 multiplier active.

Meteor Storm: fire button = accelerate. Use it through the sparse first third; let off for dodging later. Two players going through simultaneously reduces individual odds. For Memory Station: decide your goal before entering — usually Extra Life first, then cash.

Kamikaze Levels require maximum firepower. Boss levels: stockpile lives and Ship Armour. Bonus Levels: have at minimum Double Shot with Extra Bullets. Know when you're approaching a Warp and save some cash.

Hurry Up Ship: appears when you stall. Releases semi-guided missiles. Shoot it for a Rank Marker. Dodge rockets by positioning under them then swerving at the last moment. Laser Ship: park along the fringe of the beam and hammer it — Fireballs or War Plasma required, Auto-Fire mandatory. Thief Ship: steals all your money. Kill it if you can; impossible to avoid.

If your score rolls over zero — you haven't lost anything. The game tracks the full total and adjusts the display font. Rank Markers increase end-game bonus points AND can net you 1,000,000 points at Admiral rank. Shield + Kamikaze Level = obscene points.

Requires Fireballs or War Plasma at minimum. Auto-Fire is non-negotiable. Park to the side of the beam when it drops to 2/3 screen height or lower. The War Plasma beam scatter means you don't need dead-center alignment. At 1,000+ levels, the Laser Ship becomes a near-constant presence.

Catching a skull will add to the chances that extra life and cash multiplier bonuses appear.

By shooting the hurry-up ship, you can collect the rank marking that you are missing.

When a smart bomb has exploded and the gems are falling, you can collect them by holding down the joystick.

If you have a multiply bonus when entering the Meteor Storm, you may get a lot of points.

Catching a warp icon in an alien stage with a bonus level will give you a perfect score.

Red, green and blue skulls will give you a very good weapon — full fire power and the best ship speed.

When a hurry-up ship has appeared 8 times, a Money Ship will appear. Shooting this ship can give you a lot of money.

If you have a weapon type and catch the same weapon again, you will get more firepower.

Completing the Meteor Storm will give you 100,000 points and $1,000 in cash. And if you … hmm. He He..

You can figure out which skull you have not yet taken by looking at the color of the meteors in the Meteor Storm.

If you have captured 2 aliens and the scope is active, you can get a lot of points by using the aliens to clear off-screen targets.

If you have the rank of Admiral and you buy more rank markings, you will get 1,000,000 points.

Having a multiply bonus active when completing the game will give you a massive point bonus.

If you have all the rank markings for a new rank, and then buy more rank markings, you will instead buy a new rank.