Alien Syndrome/Versions

Commodore 64/128
Ported by Ace. Supports 1 or 2 players, with a single player game started by pressing fire on Joystick Port 2.

Of note, the screen-scrolling is substandard, which is a low-speed scroll that allows pressing against the edge of the screen in normal play, which is dangerous due to approaching enemies.

There is 180 seconds on the clock, with a 60 second addition for reaching the boss. Unlike the arcade version, getting killed during the boss fight due to the timer doesn't require you to restart the full stage. However, you need to rescue all of the

This port has significant changes on boss behavior:
 * 1) Asophy: The second phase of the boss is much more durable and faster.
 * 2) Hugger: Hugger only has four supporting blobs orbiting it, but they move quickly. Only two blobs get launched, but they're rather dangerous that you will need to alternate between them and the main target. If you can eliminate a few of the blobs and can get inside, you can quickly defeat hugger by rapidly firing.  Unlike the arcade version, the flamethrower is probably the best weapon as you can easily inflict damage on the orbs and keep the launched blobs at bay - or you can sacrifice a life and move behind Hugger and inflict damage without worry (although this tactic takes a full 100 seconds.)
 * 3) Tacapy: You only need to worry about hitting the body when the eyes are detached.
 * 4) Minnow: Minnow still launches a spread of shots, but no significant changes.
 * 5) Yocotie: While the attacks from the smaller holes have limited range, the main alien generally fires all the shots at you. Cover is one-way, your shots are blocked while Yocotie can return fire.
 * 6) Minenor: Only two things follow you, but they're slightly strong.
 * 7) Final boss: The suction attack is harder to dodge as the four clusters of air move more quickly. Instead of trying to dodge them, take cover in one of the corners, and move in and out of range of the attack.

Commodore Amiga
Ported by Ace. Supports 1 or 2 players, set by using the function keys. However, Rounds 4 and 5 from the arcade version are skipped. In Round 6, you're placed at the bottom-right corner of the map, requiring you to backtrack as you reach the bottom-left corner.

The time varies based on the round, but you normally receive 250 seconds on the clock. No bonus time is added when you reach the boss, and the time is reduced if you complete one of the loops. You also need to retrieve all comrades rather than just 10.

If possible, grab the laser weapon, as that does the most damage per second compared to the other weapons.

A quick boss guide based on the port:
 * 1) Asophy: The second phase of the boss is feeble. It is vulnerable when it slowly retrats to the upper-right corner, and is therefore minced in one cycle.
 * 2) Hugger: Hugger only has six supporting blobs orbiting it, and they're vulnerable to an early attack. Quickly move to the top of the boss arena, and destroy Hugger's blobs.  Once you eliminate the escort, you don't have to worry about the four tracking blobs it launches, as those leave the arena frequently.
 * 3) Tacapy: There are eight legs, but no obstacles. Destroy one side of legs on either the top or bottom, and try directing it to the same edge of the arena. Destroy the other legs, and you can hit the main body from the top or bottom.
 * 4) Minenor: With the laser, this boss is feeble as the attacks that follow you are easily destroyed.
 * 5) Final boss: The time limit of 100 seconds is more dangerous than the boss itself. The air suction is trivially dodged, but the vulnerable head on the top tends to be hard to hit.  Press against the boss and try to hit the weak point as it moves down.