Threshold (Sierravision, Cartridge)
By Warren Schwader and Ken Williams, VIC 20 version by I.C.G.
Luckily, Threshold is a little more common and I was able to snag a complete copy on Ebay for less than $90 from Canada, so it has both English and French instruction sheets. The previous owner wrote his scores down on those documents, over and over, reaching an amazing 211,100. Well, I took up that challenge and have reached a personal record of 223,400 points. This game is a tough fixed-position shooter, inspired by Sega's arcade gem Astro Blaster, and it was a 1981 hit for Sierra over on Apple II and Atari computers.
What made Astro Blaster so special among the wave of Space Invaders clones that were hitting the arcades was the unprecedented variety of ships attacking the player. Each wave had ships with different shapes, or sprites, and their attack patterns varied wildly as well. Another aspect that stood out was the overheating laser that restricts the player to more careful shots rather than just blasting away at everything as fast as possible. If the laser overheats, a message appears, and a long, arduous countdown is required before the player can shoot again.
Rounding out the features is a fuel gauge, essentially a time limit that ticks down slowly but once empty the ship is lost. After every four waves, the player auto-docks with a mother ship that refills the fuel tank and awards the player bonus points for any fuel left. It should be noted here that in Astro Blaster, the player must maneuver the ship to dock successfully and can actually fail, like in Moon Cresta. Making it automatic in Threshold, in 1981, turns it into an animated cutscene. Again, in 1981. It's okay to be awed by things like this in early computer game history. The fuel gauge-time limit is fair and not that restrictive unless the player is constantly losing time waiting for the overheated laser to cool down. So, an initial strategy tip - don't overheat the laser.
On the Commodore VIC 20 the player’s ship is green, as are the borders of the screen. The top edge is made up of alternating green and red lines for some jolly reason. The enemies, their shots the player’s shots, and the scrolling starfield background are all black and white. It works, because of the enemy variety and because the gameplay shines.
Twenty-four different enemy types await the Commodore VIC-20 user, all of which are just animating shapes - some may look like recognizable things like birds or anchors, but others are vague geometric doodles. The game's designers admitted that they got that idea from Astro Blaster and it sure beats the rows and rows of the same drones lined up in Space Invaders. The player is invited to keep playing just to see what wacky shapes the next wave of ships will have. Look, before you judge, we were starved for new games and new gameplay ideas most of the time back then. Having multiple new things to see deeper into the game was a motivator.
Let me note here, as someone who has reached the last wave in both the Commodore VIC 20 and Commodore 64 versions of Threshold, an amazing fact that has gone undiscovered (probably) for over four decades:
The Commodore VIC 20 version of Threshold has more levels (24) than the Commodore 64 version (20).
It's almost inconceivable that the VIC 20 version is better but there it is. The Sierra guys perhaps phoned it in on the C64, who knows? I actually did note all of the Commodore 64 waves back in the late 1980s or early 1990s, jotted them down on a tiny piece of paper, and stuffed it into a manila folder, to be stored along with folders for other games like The Bard's Tale. I was pretty meticulous back then.
On top of the varied shapes, there are also four different attack patterns at play in the VIC 20 version scattered across the 24 waves. It took some playing to figure that out, so at first I was overly in awe at the prospect that a game from 1981 has enough programing chops to give each type of ship its own personal AI. However, the four attack patterns repeat throughout the game, and two of them are very similar.
The main pattern is simple bobbing in formation, sending shot after shot down at the bottom of the screen. Most of these bobbing formations will send squads of 1 -3 ships down at the player in fast, jerky motions that are hard to hit before they disappear off the bottom of the screen and wrap around back at the top. Oh yes, they can shoot while coming down at the player. A few of these type of formations do not send ships down at the player, so these are the first two types of attacks one faces.
My strategy for the bobbers is to fight my way to one side, usually the left, and work my way in, shooting the outer ships in the formation with hit-and-run shots. One has to dodge the ships that break formation and head down toward the player and get shots in when they can after they pass. The overheating laser encourages patient shooting anyways, so the trick to the hit-and-run tactic is to avoid getting too greedy. Hit and run, not hit and get cocky and peel off a few more shots and oh crap I can't dodge that, is the key tactic here.
Next up are the swimmers, a large formation that slowly moves to the left and off the side of the screen, wrapping around to emerge on the right side, all the time raining fire down on the player. Sure enough, one of these guys can suddenly turn back the opposite direction for that extra dose of Threshold danger. As soon as this type of wave starts the player needs to blast away some foes to clear out some space, and then catch the wave as it passes by each time. This type of wave necessitates rapid-fire shooting right away just to survive, so let loose but back off if you see the laser temperature getting close to an overheat.
The final type and perhaps the most dangerous are the cascaders. This entire formation tumbles down the screen, off the bottom and wrapping around at the top. Couple that attack pattern with very, very spastic squads that break away for a huge risk of collision attacks here. For this I save the game's warp button (the spacebar) which slows down the entire screen except the player for a few seconds, allowing the player to pick off a few extra enemies. The warp is only available once every four waves and is recharged at docking/refueling, so saving it for these assholes, and using it at the optimal time during the wave, is highly recommended.
Speaking of docking, I encountered a bug that locked the game up. It appears that if the player has their ship in the exact position it needs to be for docking when the docking cutscene starts up, the VIC 20 can't handle it, scrolls the ship to the left side of the screen, and freezes. While I have lauded the game's variety and AI for 1981, it should also be noted that a good portion of the challenge of this version of Threshold comes for poor shot collision. The player sees their shots repeatedly pass through the wacky animated enemies, and even some of their shots that I thought had me did not make contact. To get good at Threshold on the Commodore VIC 20 one will have to take this into account, especially on enemies with small or thin shapes.
As with any shooter, practice makes perfect, and after many sessions on the Commodore VIC 20 version of Threshold I can say that most of the times I died it was my due to my own carelessness. The player starts with five ships and extra ships come rarely - at 50,000, 150,000, and every 100,000 points after that, and oh yes you can be spawn-killed by these spastic shits. The game does not have the programming to consider such trivialities, so respawn guns blazing and be ready to move.
Threshold is peak Space Invaders clone, demanding masterful shooting and swift evasion as well as a shipload of patience. The Commodore VIC 20 version is advanced for its time, even having a pause feature, but is still saddled by some of the system's limitations. The sheer joy of working through all twenty-four levels like a campaign, only to see a simple message of "GREAT!" at the next docking screen before it starts all over again at the same difficulty, was indescribable.
Having a boxed Sierravision game on my VIC 20 shelf is pretty nice, too. I could get used to that.
