The GG stands for Galvanic Gunner.
Introduction
GG Aleste II, released as Power Strike II in Europe (not to be mistaken for the SMS game Power Strike II), is a 1993 Game Gear shoot 'em up game developed by Compile and published by Sega. One of Earth's armored defensive satellites, Algo, has an unknown object attached to it. Pilot Alice Pfeiffer Wizn is alerted to the threat and heads off in the prototype Aleste ship Lance Bird. The game plays like the earlier Aleste games though the length is a more manageable 20-25 minutes for a 1 credit clear rather than the other games having a Zanac length of completion time.
I got interested by this game when M2's Aleste Collection was announced with a new Game Gear game included, GG Aleste 3. While I haven't got my hands on the collection myself I did try out the older games that were part of the collection. GG Aleste II is probably my favorite of the older games since it's very fast paced and fun to play for the entire game's length. The fact that the Aleste Collection also has a speed run mode for the older games means that there are some videos out and replays out there that I can compare a TAS to in terms of how much the time can potentially be pushed. I will note that this submission goes with the Power Strike II name as the default region coding for BizHawk goes with the European region settings.
Though as I mentioned, I do not own any version of the Aleste Collection. Thus I can only work with whatever 1 credit clear videos for Mania mode are out there done on the Aleste Collection version of GG Aleste II. I cannot guarantee that I do have a time that beats all known records as that would involve having to buy the same game three times to check their individual leaderboards. That being said for the
fastest RTA time I could find being faster by 3 minutes under M2's RTA times makes me confident that this TAS is pretty optimized.
Run notes
- Emulator used: BizHawk 2.9.1
- SMSHawk core
- Plays on Mania, the hardest difficulty
- Sets speed to 8
- A lot of RNG manipulation though generally doesn't affect completion time
Rough RTA time: 17:53.532
Mechanics and techniques
Why time was the goal rather than score
I know there are probably some folks wondering why a shoot 'em up TAS aims for fastest completion rather than maximum score. There's a reason for that. This game has an unfortunate method for infinite scoring. There are three factors at play:
- Bosses don't have a timeout mechanic
- Power ups regularly spawn at timed intervals
- Power ups always give points when obtained
Those factors combined mean that to get maximum score, it would involve intentionally not killing a boss and slowly getting power ups. It's an incredibly tedious process for infinite score. This is also why the leaderboards for this game on the Aleste Collection rank by 1 credit clear times first before scores that don't clear the game.
How Real Time Attack is measured
M2 has a built in timer in the Aleste Collection. For GG Aleste II, the timer starts upon entering the weapon select screen and ends on the frame the final boss dies. I did have to use RAM watch to determine the exact frame that the final boss does die. The TAS time does end up faster than the RTA time though the end of TAS inputs is done in a way to optimize RTA time.
Here is my
personal RAM watch file that has the address for the final boss's HP. I'm not sure if it would be the same every time, though, as that address is also used for other variables.
Power chips
At certain intervals a spinning cylindrical carrier shows up. When damaged enough it will spawn a power chip, up to 4 per tube. These power chips have multiple purposes:
- The regular gun is powered up, requiring more chips for higher levels and maxing out at level 3. This is very helpful for dealing damage.
- Every 20 power chips earns a shield. While a shield is currently active, this still counts up to 19. Thus obtaining power chips with a shield active can still let the player quickly gain another shield if they lost their current one.
- Every 32 power chips earns an extra bomb. This one is extremely important for certain boss fights in the TAS.
Special weapons
The game has 4 different special weapons. One of them can be selected at the start of the game but can be swapped out by grabbing the appropriate power ups. Special weapons can be powered up by grabbing the big special weapon power chips, up to weapon level 4. Swapping between weapons doesn't diminish weapon power but losing a life does lower the weapon's power level.
- Neo Napalm Gun
- This weapon launches a number of bombs forward at an angle. Once the bombs land they send a big fire explosion forward that deletes smaller projectiles. This is the safest weapon of choice for 1 credit clears for its power and bullet clearing properties. However the explosions do create lag.
- Hammer Hawk
- This weapon launches homing missiles from the side of the ship. It's an average weapon that isn't too powerful.
- Delta Form
- This weapon sends an orbital around the ship. The orbital has contact damage and can also shoot. At higher levels there are more orbitals and at max level moves faster. This is the weapon of choice for the TAS as the contact damage is pretty high and requires less active shooting. The reduced shooting decreases the amount of lag.
- Rising Masher
- This weapon fires an array of piercing lasers forward in intervals. This is good for screen clearing but is outclassed by the Neo Napalm Gun due to not having bullet clearing properties.
How the game handles lag
This game actually has two types of lag. The first one is one where input polling is technically lost but is compensated by taking the input of the next frame and using it in place of the lost input. This type of lag ultimately doesn't lose any time and keeps the game running at full speed but it does make some inputs a bit more funky.
The second type of lag happens when there's a lot more going on in the game. This creates actual game slowdown. Although inevitable at times the best way to prevent this is to take out enemies and other objects on screen as soon as they appear. This is the type of lag that's generally avoided in this TAS.
As a note, the bombs do generate a lot of slowdown lag but their power for some bosses end up saving time in spite of the lag generated.
Stage by stage notes
Stage 1 - Space Plant
This is a pretty straightforward stage with ample time to power up the Lance Bird's weapons. The midboss has 4 different parts to destroy before moving on. Delta form contact damage helps with reducing shooting as well as tearing through the bosses. The stage boss doens't enter its second form as the arm is never destroyed before the boss dies.
Stage 2 - Ground Base
The midboss is fought near the start and near the end of the stage but the methods of fighting it is still the same. One of the boxes contains a 1 Up but I grab it too fast for the icon to show on screen. The stage boss only starts taking damage to the body when the green eye is destroyed, making that eye a priority.
Stage 3 - Bionic City
The midboss right before the stage boss is taken out quick enough that the game doesn't stop the screen scrolling. The stage boss is vulnerable in the weird vacuum head part.
Stage 4 - Ancient Ruins
The main body of the stage boss is only vulnerable when 3 metal rings orbiting the boss are destroyed. While bombs create a whole lot of slowdown lag, it ended up being seconds faster for every use on the stage boss. It's still possible to get hit during the stage boss's death animation so watch out.
Stage 5 - Cyber Road
The first phase of the stage boss is handled with a bomb to damage the hands while they're off screen. The second phase requires breaking the other parts of the arms before harming the main body.
Stage 6 - Inner Algo
A bomb and some repositioning was used to end inputs early on the second phase of the final boss as extra inputs wouldn't result in a faster boss kill. Thus TAS timing ends up faster than RTA timing due to ending inputs early. The RTA timing was optimized to be shorter as it's possible to end a little earlier though the RTA time is longer as a result.
Possible improvements
- Better lag management, of course. There were some parts where I couldn't figure out how to reduce slowdown lag with certain enemy combinations.
- Better boss fights. While Delta Form does a lot of damage to bosses there's the possibility that switching to other weapons could result in faster strategies. it's also possible that there can be some time saved with better orbital positioning and firing patterns.
Special thanks
gosokkyu, whose info lead me to more niche works and other parts of the gaming industry. Chances are that they'd probably want me to link folks over to
shmuplations, a site dedicated to translating Japanese coverage of old 80s and 90s games including interviews.
