Awesome, I'm happy to see you're making some actual progress. Keep it up.
As for the music question .. it's likely doable, yes. It should be theoretically possible to insert a track that's pure silence into the hack and then jump from that to the boss music given a simple $1DFB store (or whichever address controls the level's music, I'm just going off of memory).
Apologies for going all AWOL on this again, but today I finally sat down and got some work done; so far, I've finished the first two items on the list above. I also have ideas for the third and fourth items (replacing the homing attack with one involving the KooPhD beakers, and making the final attack some sort of mix of all the other ones), but I'll need to wait for Kipernal to get on and answer a question about the beaker sprite before I can start coding those. In the meantime, I'll try to figure out what's wrong with those hitboxes.
EDIT: Also, another idea for the final phase. As it is, if you have an extra hit left when it starts you can just sacrifice it to win immediately, which is sort of anticlimactic. To prevent this, I'm considering make the Doc start out at the very top of the screen when he starts the attack so that Mario can't reach him, and then have him slowly move downwards as the attack progresses. That way, you'll actually have to dodge it for a while before you can end the battle.
EDIT2: And the above idea made me realize that the springboards definitely need to be replaced, since they allow Mario to hit the Doc even when he's at the very top of the screen.
If you make the energy balls "grow" from small to big in order to create an effect that makes it look like they're actually firing out of the cannon, I'm alright with the larger ones. But if not, keep them small I say.
After spending an hour trying to figure out what was wrong (hint: if you are using a sprite that depends on the shared subroutines patch without having the patch installed, a freeze isn't all that surprising of an outcome) I got the beaker sprite to work:
Nothing overly fancy; he just fires three of them in different directions.
Originally posted by Lynnes
If you make the energy balls "grow" from small to big in order to create an effect that makes it look like they're actually firing out of the cannon, I'm alright with the larger ones.
That's actually a really nice idea and I'll be sure to implement it later, but right now I want to focus on finishing the Doc's behaviour. (only the last attack left!)
And yes, I know that drawing sprite graphics aren't exactly my forte, so I'll gladly accept better ones from someone else. However, I'd still like to keep the projectiles as 16x16, for the simple reason that it makes them much easier to keep track of. This is especially noticeable with the old final attack; before, I kept getting blindsided by orbs I didn't notice, but now I can dodge it for quite some time without getting hit fairly consistently.
Hitboxes for both the energy balls and the boss sprite itself are now fully functional. Once I have the new final attack done, I'll put up a new version for you to test; all that'll be left by then is aesthetic stuff.
Random idea I just had: if we have enough unused level messages, I'd love to do something like in the boss battles of Banjo-Tooie where the boss spouts a few lines each time he's hit. After all, the Doc doesn't seem to be the type that would shut up just for a mere boss battle, does he?
Yes, I am aware of the fact that the explosions are kind of glitchy-looking at the moment, but the explosion tile is global in the actual base ROM, isn't it? I'm also aware of the fact that some of the things fired by the boss sometimes go behind him, but I am less certain about how to fix this; I don't have much experience when it comes to messing with the OAM. Also there's a few graphical details that aren't done; there's a few shrapnel sprites that will fly off when the capsule breaks that I haven't coded yet, and I haven't made an actual death sequence yet either.
Also I think I might have gone a bit overboard with the new final attack. Please tell me if this is the case.
Much, much better than the previous version you posted. I have two complaints.
1. As I'm sure you already know, the explosion GFX are messed up.
2. I believe the final attack is just a tiny bit too hard, and I think the perfect way to fix this would be to simply reduce how often the yellow balls are shot out (as in, space them out more). It would give the player more room to work with at least.
Other than that, I think it's great now. It looks like all you really need is a death sequence and a couple of aesthetic touches. Keep it up!
Hmm, I'm a bit concerned about the difficulty of hitting the boss's head; it just seems way too simple. The player can easily run to the springboard before the doctor appears and always manage a quick hit, assuming he teleports to the correct side of the room. Normally, I'd let this slide, but seeing how this is the second to last boss an exploit such as this should be fixed. If you ask me, I think that the fight needs something to deter these actions... maybe a force field above the doctors head every other attack or something?
Better yet, what if the boss pulled a Kaos from DKC3 and caused an electric beam along the floor for a hit or two? Perhaps that homing thing he spawns could instead be a platform that flies around the room?
I have to admit, I kind of agree with Lynnes here (and why I didn't point it out in my previous post is beyond me). I think the attacks themselves are good, but giving the Doc temporary invincibility, a force field, or something to prevent him from getting destroyed the second he pops up might be a good idea.