Post subject: Contra: The Alien Wars
Joined: 11/20/2004
Posts: 236
Location: United States
AKA Contra Spirits, AKA Probotector 2. It's a Super Gameboy port of the original Super Famicom game by Factor 5. There's a few key differences between this version and the original game. For example... General - Things are all scaled down for the small screen. - Things move much slower. Especially the player. - The overhead levels don't allow you to duck down, making avoiding bullets very irritating at times. - All parts of a boss need to be destroyed before the usual "core" part can be attacked, just like in Operation C. Weapons - All guns fire much slower. Even tapping the fire button doesn't speed anything up. - Area Bombs make the screen flash once instead of having a unique explosion. You can only carry five at maximum as well. - The Barrier now damages enemies instead of immediately killing them. - The Spread Gun fires three projectiles instead of five. - The Homing Gun and Crusher (?) Gun have no unique projectiles. - The Flamethrower is WAY more powerful than ever! - No Laser Gun! Levels - Level 2 does not rotate and seems mostly intact, though the end boss is a bit different in that its pods rotate around its body, don't leave power-ups when destroyed. - Level 3's smaller robots before the main boss are gone. ( :( ) - Level 4 is missing completely, replaced by the alien hive overhead stage. Level 4's end boss is almost entirely different. It's kind of a rehash of Level 2's boss, but the pods aren't the thing you're firing at. Instead, it's four eyes. - Level 5 (the original's Level 6) is slightly different. You fight THREE Red Falcon Brood Queens, no Red Falcon Heart, the usual Red Falcon Visage (with different tactics), and no Red Falcon Core! ( :( #2.) And that's the last stage! Now, I haven't noticed any outright over-looked bugs (aside from the Flamethrower doing FULL DAMAGE at ANY range and a LOT of it!), but it could be an interest run all the same, I feel. What do you folks think?
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I think it sounds like a watered down version of Contra 3 (and unsurpringly, it is). I don't think there's any point in this when you can watch a TAS of actual Contra 3 without the sucky elements like slowed down character/fire rate and so on.
Warp wrote:
Edit: I think I understand now: It's my avatar, isn't it? It makes me look angry.
Joined: 1/23/2006
Posts: 352
Location: Germany
Yeah, so much slower doesn't sound good.
Sir_VG
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Joined: 10/9/2004
Posts: 1911
Location: Floating Tower
Ugh. Both this and the GBA version suck.
Taking over the world, one game at a time. Currently TASing: Nothing
Judge, Skilled player (1278)
Joined: 9/12/2016
Posts: 1645
Location: Italy
Judge, Skilled player (1278)
Joined: 9/12/2016
Posts: 1645
Location: Italy
I recently figured that a lot of things can be optimized with some effort, so I decided to get serious on this, even if it's still my very first TAS project. I don't know if I can succeed in getting all the needed data by myself, so I ask if someone wants to help me. In my opinion, working on this TAS is worth the effort, just check my WIP movies and decide. First, I'm still trying to figure what triggers the double jump bug that I use at 4515 and 4543. I already found that it doesn't trigger unless the player is not rising in altitude. This can be checked on value at address FFE4. In other words, this signed value must be equal or greater than zero. This bug may be useful because it can be also triggered in third level. Second, I haven't still found the X and the Y player subpixel addresses. These two are the things I need help at the moment. And there are some project notes if someone is interested: The most important thing I'm working on is luck manipulation of the Crusher gun. Its explotions depend on the value at address FFE7, wich is predictably altered for every of the four explosion following the impacting projectile of Crusher gun. Other events that alter this value are all the game animations wich use random variations, such the multiple explosions (like when a boss dies), and earthquake animations, wich are also triggered when using a Bomb, tough it isn't worth wasting them. So the only efficent way to luck manipulate the Crusher gun, is by firing extra bullets in advance. Btw, I don't think I need help on this, I'll just write a brute forcing script (I alread wrote and used some). About the possible improvements: I found the Crusher gun to save a lot of time on the second mid-boss fight in the third level (the one that climbs the skyscraper) and thus is worth using it instead of the Fire gun, even if this will make lose some frames with the level boss fight. I also have to try using it aganist the second level boss and see if I can spare some Bombs for other uses, before and/or after the boss fight. Lastly, here are the useful RAM values I found:
SystemID GB
C4B5	b	s	0	System Bus	Enemy 0 HP
C4B6	b	s	0	System Bus	Enemy 1 HP
C4B7	b	s	0	System Bus	Enemy 2 HP
C4B8	b	s	0	System Bus	Enemy 3 HP
C4B9	b	s	0	System Bus	Enemy 4 HP
C4BA	b	s	0	System Bus	Enemy 5 HP
C4BB	b	s	0	System Bus	Enemy 6 HP
C4BC	b	s	0	System Bus	Enemy 7 HP
C4BD	b	s	0	System Bus	Enemy 8 HP
C4BE	b	s	0	System Bus	Enemy 9 HP
FF97	b	u	0	System Bus	Level X
FFDF	b	u	0	System Bus	Player X
FFE0	b	u	0	System Bus	Player Y
FFE4	b	s	0	System Bus	Vertical Speed
FFE7	b	u	0	System Bus	Random Seed
my personal page - my YouTube channel - my GitHub - my Discord: thunderaxe31 <Masterjun> if you look at the "NES" in a weird angle, it actually clearly says "GBA"
Fortranm
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Joined: 10/19/2013
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Good luck on optimizing this game. It is surely a watered down version of Contra 3, but it has much higher playability than the port on GBA does.
Judge, Skilled player (1278)
Joined: 9/12/2016
Posts: 1645
Location: Italy
Fortranm wrote:
Good luck on optimizing this game. It is surely a watered down version of Contra 3, but it has much higher playability than the port on GBA does.
Thanks. I think this game shouldn't be compared to its SNES counterpart, because its gameplay is so different that it actually makes it a different game. Also, I think it is incorrect to call it a port, like it would for the GBA version: it is more like an adaptation for Game Boy. By the way, here is an encode of the last WIP file I provided: Link to video
my personal page - my YouTube channel - my GitHub - my Discord: thunderaxe31 <Masterjun> if you look at the "NES" in a weird angle, it actually clearly says "GBA"
Judge, Skilled player (1278)
Joined: 9/12/2016
Posts: 1645
Location: Italy
Good news! I started a new run from scratch and I discovered many things that allowed to save many frames! Here is the new WIP file: http://dehacked.2y.net/microstorage.php/info/238071480/Contra%20-%20The%20Alien%20Wars%20%28USA%29_WIP7.bk2 and here is an encode: Link to video Summary of improvements: 2 frames saved in main menu 2 frames saved by destroing the two barrier in the first level faster[/list] 4 frames saved by using a new glitch with Spreader gun About the new glitch: First, note that the 4 frames of improvement are relative to my best attempt done during my huge luck-manipulation bruteforce trials. This is probably going to simpifly my work a lot! By the way, let's go to the facts. This trick involves a glitch triggered with the Spreader gun. Normally, you have to wait more than 5 frames before being allowed to fire the next shot, except in the case there already are 3 bullets on the screen AND all the 3 bullets of the last shoot have hit an enemy in the same moment they were fired. In this case, the gun will automatically fire again in the next frame, until you release the B button. This allows you to deal 3 HP damage every frames to the target, which is now the strongest way to attack in the game, even stronger than Fire gun, wich can deal a maximum of 5 HP damage every 2 frames. Now I have to test wich weapon is faster for defeating the boss of level 2. I hope it isn't the Crusher gun, otherwise I will be forced to use it again for the level 1 boss... and continue with the brute forcing. Edit: I forgot to mention something: I decided to go for the highest score possible allowed without sacrifincing frames, and this already resulted in a more entertaining movie, to me. (everyone likes violence, after all) And this is the new .wch file. Note that I found the subpixel values, wich are equal 1/16 of pixel.
SystemID GB
04B5	b	s	0	WRAM	Enemy 1 HP
04B6	b	s	0	WRAM	Enemy 2 HP
04B7	b	s	0	WRAM	Enemy 3 HP
04B8	b	s	0	WRAM	Enemy 4 HP
04B9	b	s	0	WRAM	Enemy 5 HP
04BA	b	s	0	WRAM	Enemy 6 HP
04BB	b	s	0	WRAM	Enemy 7 HP
04BC	b	s	0	WRAM	Enemy 8 HP
04BD	b	s	0	WRAM	Enemy 9 HP
04BE	b	s	0	WRAM	Enemy 10 HP
04BF	b	s	0	WRAM	Enemy 11 HP
1727	b	u	0	WRAM	Bullet 1
1730	b	u	0	WRAM	Bullet 2
1739	b	u	0	WRAM	Bullet 3
1742	b	u	0	WRAM	Bullet 4
174B	b	u	0	WRAM	Bullet 5
1754	b	u	0	WRAM	Bullet 6
15	b	u	0	HRAM	Level X (x16)
17	b	u	0	HRAM	Level X
19	b	u	0	HRAM	Level X (/16)
16	b	u	0	HRAM	Level Y (x16)
18	b	u	0	HRAM	Level Y
1A	b	u	0	HRAM	Level Y (/16)
5F	b	u	0	HRAM	Player X
16EC	b	u	0	WRAM	Player X (/16)
60	b	u	0	HRAM	Player Y
16ED	b	u	0	WRAM	Player Y (/16)
64	b	s	0	HRAM	V. speed
67	b	u	0	HRAM	Random
Edit2: some copyedit... Edit3: It keeps getting better! I managed to cut 4 more frames by optimizing the boss fight! Here is the movie file: http://dehacked.2y.net/microstorage.php/info/765561410/Contra%20-%20The%20Alien%20Wars%20%28USA%29_11.bk2 Btw, it seems there is something wrong with the hoster's engine. It says the movie has 6088 frames, but there are actually 6014 in BizHawk.
my personal page - my YouTube channel - my GitHub - my Discord: thunderaxe31 <Masterjun> if you look at the "NES" in a weird angle, it actually clearly says "GBA"
creaothceann
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Judge, Skilled player (1278)
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Posts: 1645
Location: Italy
creaothceann wrote:
Why not play it on the Super Gameboy?
Because the palette suck and has no custom border.
my personal page - my YouTube channel - my GitHub - my Discord: thunderaxe31 <Masterjun> if you look at the "NES" in a weird angle, it actually clearly says "GBA"
Judge, Skilled player (1278)
Joined: 9/12/2016
Posts: 1645
Location: Italy
ThunderAxe31 wrote:
First, I'm still trying to figure what triggers the double jump bug that I use at 4515 and 4543. I already found that it doesn't trigger unless the player is not rising in altitude. This can be checked on value at address FFE4. In other words, this signed value must be equal or greater than zero. This bug may be useful because it can be also triggered in third level.
So yesterday I finally uncovered the mystery! When the player begins falling by walking off a platform, a 10-frames countdown will begin. during this time, you are allowed to jump even if you aren't actually standing on your feets... The curious fact is that this countdown will pause during the jump and while you're on the monkey bar. It will resume whenever you begin falling again, but you can use it again before it goes to zero so... You can jump again on air. In pratice, you can always jump if FFE4 (signed) is >=0 and FFE3 (unsigned) is non-zero. This is going to save a lot of time in level 3! Edit: oh and I almost forgot, here is my new level 1 WIP: User movie #39493171658302538 I saved only 3 frames because the boss got problematic with its timing. Unfortunately, it's probably impossible to fix.
my personal page - my YouTube channel - my GitHub - my Discord: thunderaxe31 <Masterjun> if you look at the "NES" in a weird angle, it actually clearly says "GBA"