I'd like to thank Aqfaq for endless encouragement, watching my progress closely, offering knowledge about the game, and being awesome.
This TAS was recorded on Gens 9z / 9.5 in front of a live studio audience.
Sub-terrania is similar to Solar Jetman for the NES. The game was a real challenge to optimize, and there surely is more improvement to be found. I think this game would be a good candidate for an "open-source" TAS in the future.
Most levels have a set number of goals, which usually consist of rescuing some miners, collecting items, and sometimes destroying a large enemy. After all the goals are completed, the message "Mission Accomplished" appears, and the level ends after returning to and landing on the starting platform.
There's a lot of on-screen info, but here's what's useful:
- Fuel is the red bar in the top-left corner. It's constantly decreasing, but at a much more rapid rate when using the throttle. If it runs out, the ship explodes. (Great design)
- Gun energy is shown below fuel (next to "MEGA"), which increases until a limit, based on weapon level, and resets after each shot. If used at full power, it shoots six particles out, four in front, two angled backwards.
- Ship energy is shown in the lower-left corner - as the white ship outline fills with red as damage occurs. This energy gradually recharges.
I also used the Gens Input Animator to do some fun stuff. Unfortunately, 3-player controller mode freezes this game's controls, so I do not have access to all the pretty colors that it has. To see the input animations, enable the "Show Input" checkbox in the menu under Options -> General.
Thanks for watching!
Details of each level follow, so beware of spoilers(zomg).
Level 1
- Rescue POWs
- Collect Sub-Module
Most of the ship's energy is spent saving a few frames picking up the POWs. Notice that only two of the three are needed to fulfill mission requirements. Cya Earl! After collecting the Sub-Unit, death is used to warp back to the beginning platform quickly. Optimizing death involves creating the smallest explosion possible, as the screen doesn't fade out until the rubble has quieted down.
Level 2
- Destroy Doomsday Device
- Rescue POWs
- Collect Sub-Module
This level is mostly about destroying this big 3-headed floating tentacled boss. The left and right faces, and the bottom tentacle "face" must be destroyed individually, then the boss becomes an entire target to destroy. Upgrading to weapon level 2 is faster overall due to the time needed to wait to charge up the weapon for the first couple hits. The boss's death opens up the area with the other goals to collect.
Level 3
- Destroy Alien Housing
- Rescue POWs
- Collect Sub-Module
This is one of the longest levels. There's a huge laser cannon which needs to be deflected in various ways to access all parts of the level. First, the laser is diverted to allow landing on a platform that removes a barrier. Behind this barrier is another deflector that's used, but first, some more fuel and energy are collected to use later.
Now the laser is deflected into a new barrier, which exposes the alien home that will destroy, because aliens sitting in their own house is a threat. The first hit starts a small cut-scene which removes the barrier in front of this laser cannon, however, the ship can still be turned and fired during this time.
Turns out that the house only had a new deflector in it, which is used to destroy the laser cannon, and grab the POWs and Sub-Unit behind it. Dying here is very slightly slower than heading back to the start, and also reduces the weapon level gained in the last level, which will hurt on the next level. Fuel is very scarce at this point, so a few places conserve it and travel on momentum.
Level 4
- Destroy THE THING
- Rescue COMBAT SQUAD
- Collect SUB-MODULE
Despite what the mission statement says, the boss here does not need to die to accomplish the mission, so this ends up being a very fast level. In fact, the first six levels are all contingent on rescuing POWs and collecting the Sub-Module, but some levels put other obstacles in the way to get those to happen (like level 2's boss).
There's a weapon upgrade here, but it doesn't save any time since the boss here is going to be little more than scenery. The POWs are rescued first, and then the big building is partially destroyed to burrow a path to the sub-module, while THE THING watches on uselessly.
Level 5
- Destroy NUCLEAR POWER PLANT
- Rescue ENDANGERED WORKERS
- Destroy ALIEN LIFEFORM
- Collect SUB-MODULE
The NUCLEAR POWER PLANT holds the key to destroying the ALIEN LIFEFORM, which is blocking the SUB-MODULE, so these listed goals are actually needed in this level. To make it even more painful, there are nine ENDANGERED WORKERS, and they all must be rescued.
The POWs come first, and the stops are a bit longer since we needed to wait for all of them to pile onto the bus. There's a weapon upgrade to be had right by the second stop, followed by a refueling.
The next weapon is used to remove the force field around the power plant, which allows damange to be made to a small chunk which contains...a giant spiked ball. The amount of fuel needed to move this "nuclear charge" is massive, which is why fuel was needed earlier. This item is the only way to destroy the alien on the other side of the cavern, which opens up the sub-module, and from there it's a quick trip back to the landing pad.
Level 6
- Destroy GUARDIAN ROBOT
- Rescue SURVIVED MINERS
- Collect SUB-MODULE
Like Level 4, this GUARDIAN ROBOT does not actually need to be destroyed. There are 8 SURVIVED MINERS here, and 5 need to be rescued. 62.5% survival rate sounds acceptable to me!
The walls here that must be shot are made faster by having an upgraded weapon, but they are still a pain. I selecteded the POWs based on location and one of them being next to a weapon upgrade. Another group of 2 are near a fuel refill, but I'm able to barely squeak out of here without picking it up.
The sub-module is behind a wall near the GUARDIAN ROBOT. The prisoners near the robot are saved for afterwards because the robot is in a bad position during the first visit to that area.
Dying after completing the goals is only slightly faster in the short run than returning to the beginning, and it's faster overall to keep the weapon power.
Level 7
From here on out, no more rescuing POWs or landing on platforms.
This is a relatively short level. Access to the exit is blocked by seaweed that must be made of cement and peanut butter, and the only way to move it is to drain the water by blowing up a nearby pipe, which requires a pipe bomb.
On the way to the pipe bomb, there's a Anti-pressure Device, which removes the natural buoyancy of the ship underwater for a few seconds each time it's used.
If the fire button is held when the pipe bomb blows up the pipe, the ship's velocity goes crazy. I'm not sure what causes or determines the direction of this sudden burst, but it allows passing through the seaweed before waiting for the water to lower. The level is completed by exiting a space on the very left of the level - this just isn't seen well due to the screen not being able to keep up with the ship.
Level 8
This level has my favorite music. Here, there are two option-like pods that give your ship the ability to shoot a laser upwards. This is used at the end of the level to overheat a laser cannon attached to a wall, which when destroyed, opens up the exit.
The route that is taken is the normal path, and it contains a fuel refill closeby. Aqfaq discovered that it's possible to fly straight up from the beginning to open the energy barrier from the wrong side. However, there isn't enough fuel to do this after collecting the laser power-up without dying, which lowers the weapon power, and ends up losing time overall on the final level.
The water turns acidic midway through the level - there's an Acid meter here next to the fuel and gun meters. Just another way to die in this game!
Level 9
The first thing to get here is the Nuclear Crystal. This item slows down the ship's fuel consumption rate so low that for all practical purposes, fuel is infinite, unless you go to eat the biggest sandwich of your life and forget to pause the game. This item is required because the level is absent of fuel refills and it's the longest in the game.
This level is mostly navigating through narrow, water-filled caverns. A couple keys are collected in order to remove electronic barriers. Once the path opens up, the final boss appears.
Svin
Aqfaq wrote:
- We have only four letters... so, any suggestions for the boss name?
- DEATH!
- Cool! No, wait... it won't fit...
- SVIN!
- That's it! Release the game!
This boss has two forms, and a lot of life for both. This is where the fully powered up weapon comes in handy. Dying here does not reduce your weapon power, and it does not reset the fight either. The gun power also continues to charge while waiting for the next ship to become available.
adelikat: Accepting for publication and claiming for encoding.