Introduction
Thunder Force II, also known as Thunder Force II MD in Japan, is a port of a Sharp X68000 game by Technosoft. This was released within the first year of the Japanese Mega Drive's life and was straight up a launch title for the US Sega Genesis lineup, both in 1989. Even though the port has cut levels, graphical downgrades, and various adjustments to weapons and levels, the game plays well with almost no lag. While half of Thunder Force II is a horizontal shmup a la Gradius, the other half is a top-down shooter where a map has to be navigated to find and destroy bases around the map a la Bosconian.
The game's story is about the ORN Empire attacking the Galaxy Federation with their new mothership, the Plealos (Preareos as seen in the epilogue). The mothership has destroyed the planet Reda and uses the planet Nepura (Nebula in the US manual). The Galaxy Federation sends the ship Fire LEO-02 Exceliza (Thunder Force II in the US manual, I guess since the first game never left Japan) to destroy Plealos.
I wanted to see how fast the top-down stages could be done and I came across this
cancelled submission by chis. This made for a good jumping off point for what can be done but using 18 years of tech available to me meant I could save a lot of time across all stages.
Run notes
- Emulator used: BizHawk 2.8, Genplus-GX core
- Plays on Hard, the only way to access the final stage
- Uses death to save time on the top view stages
- Aims to entertain for the side view stages to the best of my ability
Techniques used
Ship movement
Diagonal movement is slower horizontally/vertically compared to just moving in the cardinal directions when needing to head in a cardinal direction. However, this does make it possible for micro-adjustments in positioning. This is mostly relevant for playing around rather than speed. For speed, it's best to just take the most direct path, especially for top view stages.
Rapid firing
Manually pressing the button rapidly is faster than the game's auto fire. The main problem is that sometimes button inputs have to be spaced out due to shot limits for every weapon. Auto fire runs into this problem less since shots are sent out in a spaced out way such that it's not a concern for real time play.
Using deaths as a shortcut
In most of the top view stages, the only important targets are destroyed by the bombs dropped when shooting and not the bullets from the ship's current weapons. This makes weapon choice mostly irrelevant for completing top view stages. Since the screen keeps scrolling upon death in the top view stages, this makes burning some lives to reach the goals faster. The major downside is losing all pickups and being set back to the default guns. Sorry to those who wanted to see a no miss run.
Minor lag management
In stage 3 there can be enough chasers spawned by the flying enemies that there can be slowdown. I take out some of them to mitigate some lag. Otherwise the only parts with some lag is when an item drop spawns, and that's an incredibly rare occurrence.
Not picking up power ups at stage end
I only discovered this after completing stage 7 and didn't want to possibly redo stage 6 to fix the end of stage 5. Since the stage transitions are music based and the music is paused when picking up a power up, picking up a power up during the screen fadeout in top view stages slightly delays the stage transition.
Shot impacts
For the most part, it's possible to tell when a shot lands by the color of the impact. Orange indicates damage has been done to something, and blue means nothing was done. This was helpful for finding ideal positions to shoot.
Weapon breakdown
While I barely use much of the weapons on the top view stages, I do try to use each weapon a decent amount in the side view stages. They will be separated into categories. Do also note that for the top view stages, each weapon also drops a ground bomb attack for ground-based objects.
Both views
Twin-Shot
Fires two shots forward. Decently powerful enough with rapid fire and the go-to weapon for top view stages.
Back Fire
Fires one shot forward and one shot backwards. Pretty much never used in top view and very briefly used in side view.
Laser
This replaces the Twin Shot when obtained. Fires a beam that pierces most objects and hits multiple times per beam. While each individual damage tick isn't big damage the fact that it can overlap a target for a bit means that it can deal pretty reliable damage in real time play. Never picked up in top view stages.
Hunter
Fires a volley of three homing shots from the front of the ship. Incredibly weak and made weaker due to the 9 bullet shot limit on screen. Never used in top view stages.
Top view
Due to death strats used from stage 5 onwards, most of these weapons are never seen in the run due to losing them.
Wide Shot
This replaces the Back Fire when obtained in top view stages. Fires 3 shots forward in a spread and one shot backwards.
Five Wave
Fires five shots forward in a spread. Used briefly to take out some enemies.
Destroy
Fires a single shot forward but drops two additional bombs in a spread formation. While this would be nice, the spread is a bit too inconvenient to use since the spread is just a bit too far out to be convenient.
Clash
Fires circular shots that swirl forward, giving more coverage for air-based enemies and obstacles.
Side view
For the most part weapon usage outside of bosses doesn't matter since lag management isn't an issue. All of the weapons do get showcased a few times.
Mega Flash
This replaces the Back Fire when obtained in side view stages. Fires three shots forwards and two shots backwards. Decently powerful bullets but the shot limit makes it slower for anything not behind the ship.
Wave Shot
Shoots a regular shot and two wavy shots forward. Fairly powerful when all hits connect and has a good coverage area.
Side Blaster
Shoots a regular shot forward and two waves vertically. Incredibly powerful, especially if fired close enough that both of vertical shots hit the target. The go-to weapon for bosses.
Nova
Shoots a single forward shot and an aimable spread of three bullets, generally based on the opposite of the ship's movement. Since there are 16 possible firing angles and the aim is rotated rather than instant, this isn't quite as good for bosses despite its good damage.
Other power ups
These aren't weapons but I'm putting them here since they drop from the same item carriers.
Claw
Attaches an orbital, up to two, that circles around the ship. The claws can block bullets, do slight contact damage, and fire extra bullets along with the ship. For some reason, only one of the orbitals seems capable of firing bullets.
Roll
Makes any attached claws spin much faster around the ship temporarily. Useful for just a little bit of extra defense.
Breaker
Creates a shield around the ship for temporary invincibility. The color of the shield determines how much longer it will last.
1-up
Gives an extra life. That's it. Not as useful since getting extra lives from points is pretty quick in this game.
Stage breakdown
Each top and side view stage set is a level according to the game and manual. Level and stage names will also come from the US manual. I will also be listing a rough estimate of time saved over chis's run. I didn't want to try figuring out the exact numbers since I'm not a fan of figuring out GENS inputs.
Before starting
I save roughly 15 seconds due to menuing quickly and only adjusting difficulty level (an actual improvement) and starting the game right away rather than letting the title screen music play out (not a real improvement). If you really want to listen to the tile screen music tune, you can find that somewhere else I'm afraid.
Level 1 - The Planet Nebula
This is the only level available on Practice difficulty, which is a choice that could be made.
Stage 1 - The skies overhead
Simply taking a more direct path from chis's route and aggressive base bombing was enough to save roughly 23 seconds. The other improvement was not stopping when shooting the gates blocking the way.
Stage 2 - Inside of an enemy port
The first side view stage of the game. Since everything before the boss is an auto-scrolling affair I decide to play around a little bit with silly movements and close calls. I also kind of show off how much stronger the Side Blaster is compared to the Wave Shot with the mini-boss encounters. Time-wise though? The improvable part is being incredibly aggressive with the boss and manipulating boss movement, saving roughly 23 seconds.
Level 2 - The Underground City
Stage 3 - Skyscrapers
There's a small amount of lag management with this stage. Woo. Anyways, just optimizing chis's route saves roughly 6 seconds.
Stage 4 - Highway
This stage introduces increasing the scrolling speed. For being a tank, the boss sure seems to have the least health across the side view bosses. However, being too close to the right edge of the screen makes the boss refuse to approach, opting to launch missiles instead until the player backs off. Roughly 10 seconds are saved on the boss.
Level 3 - Deep Inside The Planet
Stage 5 - A cave
I think I might be broken since listening to this stage's music reminds me of
this.
Anyways I decide to take a completely different approach to this stage by going directly down-left to destroy the first three bases quickly. I couldn't figure out a fast way to reach the final base deathless in a reasonable time frame. With casting away the dreams of a no miss, I drive the ship through the meat rock walls and take out the final base in short order. This route and strat change saves roughly 37 seconds. However, picking up an upgrade during fadeout cost a small amount of time for the stage transition.
Stage 6 - Inside an abandoned pipe
The rapidly moving shutters have an exact point in the middle where they don't crush the ship. This stage also introduces the enemy that launches homing but destructible balls that I dance around. The boss is taken out in short order, saving roughly 18 seconds.
Level 4 - Anciet Ruins
Stage 7 - Statues
I follow chis's order but take an intentional death through a wall to make the route tighter. This along with destruction optimization saves roughly 24 seconds.
Stage 8 - Inside the ruins
oh no this stage is 4 minutes
The parts where the screen stops scrolling are on timers, rather than being dependent on destroying the enemies. Thus I intentionally don't immediately take them out to mess around for a bit. I also apologize for what I did with the destructible blocks before the big mini-boss. For the boss proper, along with up close aggression I adjust the ship's position such that the claws would block the bullet spreads from the boss after the lightning barriers were broken. Roughly 24 seconds are saved.
Level 5 - The Ultra Combat Weapon Fortress Plealos
This level is only available on Hard difficulty, which explains why stage 8 is at least 4 minutes long. This level also only has a top view stage where completing it ends the game.
Stage 9 - The final confrontation
In this stage all the important targets are instead destroyed with the regular gun rather than the dropped bombs. While this might imply using anything beyond the Twin-Shot, I use a lot of death shortcuts to save time. While I follow chis's barrier target order I instead head to the left after the second barrier since it's a much shorter path. I intentionally don't die immediately on the first barrier until it's destroyed since otherwise I'd have to wait on respawn time. I also skip on picking up the Breaker pickup near the fourth barrier since I managed to get all shots on the main cannon before losing the remaining i-frames from death. With all of that, roughly 39 seconds were saved.
Possible improvements
- Most obvious: not picking up that power up in stage 5 for a small time save
- Possibly tighter top view stage navigation and more efficient target destruction
- Foregoing all pickups in the top view stages, though there would be a slight problem of lag management in stage 3
- Maybe using nova a bit more on bosses could save a bit of time
- Stylistic choices in the side view stages, though that's subjective
Special thanks
- chis, for having a good starting point TAS for me to improve on
- The Official TASVideos Discord for their feedback on the first shmup section, which helped motivate me for the rest of the run
Suggested screenshots
- Frame 16810 - Dancing with the man-o-war-ish ships
- Frame 17105 - Getting between missiles
- Frame 24543 - In the area of mortar fire
- Frame 26532 - Avoiding the volley of blue orbs
- Frame 36028 - Flying through a missile barrage
