https://www.twitch.tv/videos/22646697?t=10m09s There's a glitch with the ship where you can destroy the front on a specific frame to skip the rest of the ship and go straight to the final boss.

https://www.twitch.tv/videos/22646697?t=10m09s There's a glitch with the ship where you can destroy the front on a specific frame to skip the rest of the ship and go straight to the final boss.

OMG! Wow. Thats a very nice find. Thanks for letting me know. I'm gonna cancel this and redo the ending. Propably gonna take day or two to test some stuff.

om, nom, nom

Looks like the trick to the first boss is getting the killing blow while it is moving downward ($4FA == 0xB2) and its y velocity(?) is 243 ($4F5 == 0xF3). Since this game seems to copy everything to temp addresses to do anything with them, those values end up propagating elsewhere and just happen to speed up the transition to the next stage, I guess. The thing with the ship and the final boss probably happens for the same reason, so an input file of that happening might give some clues to getting it on other bosses.

Looks like the trick to the first boss is getting the killing blow while it is moving downward ($4FA == 0xB2) and its y velocity(?) is 243 ($45F == 0xF3). Since this game seems to copy everything to temp addresses to do anything with them, those values end up propagating elsewhere and just happen to speed up the transition to the next stage, I guess. The thing with the ship and the final boss probably happens for the same reason, so an input file of that happening might give some clues to getting it on other bosses.

Wow. Thats interesting. I think you might be on to something. I did not put it very accurately in my post, but what I have found is that. There is at least two trigger spots (I have found) in first boss seperated by about 4-5 seconds. The frame that triggers the glitch is "counted" from the point that 2nd phase starts. In other words the copter has been in the exact same position doing the exact same thing when glitch is triggered (that makes your theory (and those memory addresses) very worthwhile to study). If I study the up down movement and the trigger frames of the first and last boss, It should give some answers. If the y position indeed is relevant, then there shouldn't be any possibility to trigger the glitch on level 2-4 bosses I think. Thank you very much for this interesting information.

I tried and failed to reproduce the trick with ship/final boss. Hard to say which object's properties would trigger it there since, unlike the 1st boss, there are about 4 or 5 of them. And yeah, I actually looked at the other bosses after posting and realized that since they're mostly stationary they wouldn't be likely to make it work.

The first boss second trigger spot is exactly 200 frames after the first one. And the boss is exactly at the same y position. Finishing blow must be delievered when the boss is at its (visually) lowest point and 11 frames before it starts (visually) ascending. (One cycle = 200 frames) <EDIT> Also the 3rd trigger spot is 200 frames after the second as expected. <EDIT> Time to check the ship now..

Okay. So I went through the trouble of testing every single frame from the first possible deathblow I managed to do @f#129 (from the beginning of the battle) to the last possible deathblow @f#532 (from the beginning of the battle)(403 tested frames). It turns out like has been suggested elsewhere that the glitch triggers when finishing blow is delivered at the last possible frame. I just wanted to make sure that thats the case so I tested that myself. <EDIT> I'm talking about ship battle just to make sure..<EDIT> I don't think there is need to do more research/testing? (even while not knowing how the glitch actually triggers..)

I don't think there is need to do more research/testing? (even while not knowing how the glitch actually triggers..)

That's up to you. :) I'll go ahead and check out the ship battle now that we know how to trigger it, but I agree that a fuller explanation doesn't seem likely to change much. edit: like you said, killing the bubble on the frame before it moves off screen is all it takes. It'd be nice to have a better explanation, but I don't feel like it's worth the effort here.

Wow nice finds! I haven't checked the input file itself, but still, I'm honestly surprised there's still relatively many improvements possible. Iirc, when I was TASing this, stages 2 and 3 lag reduction was rather tricky, since RNG also needs to be taken account for drops. For instance, from the published run, I could've made it past the first cliff area at stage 2 (the one with the vertically extending enemies) a tiny bit faster, but resulted in worse luck, so I had to abandon it. I'm so glad you managed to soldier on this. :)