I've thought about that, and experimented a little. once again, the physics get in the way.
Holding two different direction buttons at once doesn't do anything too useful, so no good left+right or up+down glitches.
I'd love for there to be some input/cancellations that makes Sonic come to a complete stop. I only know of one, the orange shield power up that can make you dive downwards, canceling all X/Y speed. But that shield does not appear everywhere, and even then is out of the way of the fastest route. (edit: I just watched volcanic valley 2. There is an orange shield on the way :-P)
When they introduced the 3D element, they removed the 'polar grid' of Sonic's 8 directions. Sonic may have 8 directional movements, but his movements are not just limited to those 8 directions, they very often steer off course. That sounds complicated, so let me explain.
The turning in the game is very counterintuitive. When sonic is in a complete standstill, if you hold the direction he is facing, he will run forwards in that direction. However (and what makes this game incredibly difficult) his turning does not work the same way as other 3D games. if you start turning to Sonic's right or left, he will make a wide arc until he eventually is going to intended direction.
When it comes to making 180's, he sucks.
(lame drawing, but just to get the idea across.)
If you are holding up, then let go and start pressing down, Sonic will spin around on his right leg as a pivot, swing around and do a 180, then start accelerating in that new direction. he will now be lateral with the first direction he was facing, except displaced to the left/right. He will *literally* do a U turn, and not go the opposite direction on the direct path that he just came from, which is why the game is so difficult to play. When you are at average speeds, and trying to collect something small, like a Flickie, you will run towards it, overshoot, turn around to get back, but you're turning puts Sonic on a new trajectory, and you try to re-compensate, but that makes Sonic miss again and he has to turn around, etc. etc. etc. In real time, it can take me 10+ seconds to get a Flickie.
This is what it looks like trying to catch one Flickie in the center of the field:
Even when in a standstill, pressing a direction for 1 frame does not turn Sonic completely in that direction. You have to hold it 3-4 frames, and his X/Y positions will have changed in the same U turn style as if running (pivoting around his foot), so I have to take that into account too.
Now, complete halt? here's where it gets even more tricky.
The best idea to come to a halt is to *brake* by holding the opposite direction, right? This unfortunately causes the U turn problem that I mentioned earlier. I could be heading straight at a robot, do a U turn before I hit him, start to dash to kill the robot, and by the time I've stopped, I'm about 5 feet away from where the Flickie lands in a direction I was never even pressing. I have to test all sorts of unorthodox angles/braking techniques in order to get that dead-halt right after I hit a robot, and usually that does not work so well.
But, knowing what I know now, here's what I would *like* to happen (and some things that I to not work:)
-rolling is very bad, when your intent is to make sudden stops. when rolling, Sonic usually likes to keep rolling, even if his speed is very slow, and he hates turning (this applies to spin dashes too. These are both forms of rolling that are very straight sensitive; when you start to turn, your speed starts dropping). what is most aggravating is you can only charge a spindash when you are completely stopped, and going from a roll to a complete stop requires braking and losing speed about 10-20 frames before my intended target. I can be going at a speed of 10, press B, and Sonic will curl and roll slowly forwards at snail pace, not charging up a spindash. (Pressing A/C will make him jump.)
-Jumping cancels all roll/spindash effects, so my guess is that jumping might be the key here to quick stops. But the jumps are just as quirky as Sonic's running movements, so jumping and ending up where you want to be are two completely different things, especially when not jumping in a straight line.
-"braking"- i.e. holding opposite directions so that I decelerate enough when I reach the robot- works sometimes, I'll start a roll one frame before I hit a robot, and 10 frames before that I'd have been holding the opposite direction. Sonic usually overshoots the landing spot of the Flickie, and I have to adjust even more to compensate.
So I suppose that I just have to watch SprintGod's videos closer (he makes many major mistakes in Flickie collecting; sometimes the slipperiness gets the better of him and he loses 1-3 seconds, other times he is spot on and loses no time in jumping, collecting, and running to the next destination), and at each robot test to see what is the most optimal way to slow down and either stop for a spindash to the next destination, or to jump and start running there (as I did for the most part in my WIP.) In my revised WIP, I've so far gotten 2 successful stop/spindash/collect Flickies done, which is good.
But I like your idea of mentioning *now* of exploiting the game engine to create instant stops at high speeds, which the other sonic games offer, but I think this game is just too slippery and the controls built to resist such beneficial movements.
In 3d blast, the controls are very slippery; in order to start a spin dash you have to be at a complete stop, which is near impossible to do when trying to slow down from running. the 3d means that you have to turn left, right, up, or down, or go on diagonals.
spindashing requires you to wait for a Flickie to settle down and land on you. sometimes it is impossible to stop, and make a spindash charge up in the direction and have the Flickie land right on top of you. Sometimes it's just faster to jump up and start running, especially if the next destination is short and has lots of turns involved.
My last gripe about spindashing is that it makes hitting the next target harder. when rolling you'll hit the robot, but coming to a complete stop when curled is near impossible, since again, slippery physics and sonic has this personal gripe about coming to a complete stop quickly.
But these are my initial observations. In redoing GG1, armed with the speed memory address I should be able to save a lot of time, with optimizations that I found. Expect tighter play and more/better spindashes.
MAJOR EDIT: I found the mem address for speed, and I made comparisons as to what is fastest in each situation. So I'm going to redo the entire GG1, based on these findings:
Speed: 00FFC204 1 un/signed (I think these both give the same value.)
Max speeds oscillate. Letting go of directions does not give the same Super Mario World effect, so no 'hop glitch", unfortunately.
All "slope" effects increase/decrease based on the steepness of the slope. Going down steeper slopes gives higher speeds, going uphill negates speed. Commonly you can go down hills so fast that you will be running in mid air.
-Max running speed takes 36-7 frames to attain from a complete stop.
-Max running speed: 76-79 (varies).
-Speed when jumping at max running speed: 77-79
-Acceleration gained from jumping is less than acceleration gained form running.
*Jumping before max speed is reached is slower than running to reach max speed.
-Rolling down slopes speed: 79-82
-Jumping on a down slope, when rolling/running at max speed: 100+ slight boost
*This is a slight 'boost' in speed; it brings the speed to 100 instantly, and then in ~10 frames the speed drops back down to normal max jumping/running speed. It is always worth it to jump when running down hills, not matter how small the slope may be.
-Running uphills: 75-79 (based on steepness. Jumping and rolling up hills is to be avoided entirely. Only run or spindash up hills.)
-"optimal" spindash: 119, slowly decreases by 1 over time (moreso when going up hills)
(note: A and C are the same button in this game, alternating A and C to charge up faster does not work.)
-from a standstill, an optimal spindash takes ~16 frames.
-spindashing down slope jump speed: 127 boost
-You can bounce into walls, and this will rebound you, keeping the same max speed with which you hit the wall.
-When at max speed, if you bounce off of an item or enemy, you do not lose or gain any speed.
-Turning causes a centripetal affect, in that the faster you turn, the more you slide, and your desired speed decreases. It is best to never switch immediately from one direction to another without first using the diagonals to 'ease' your way to your desired direction. This lessens the decrease in speed the most.
SO, I am going to redo, knowing full well that with this knowledge and these guidelines, I can save time, most likely more than 1 second, especially since 10 seconds into the course I already have ~20 frames saved, and that was in an already tight spot with mostly uphills and flats, no downhills.
