I've spent the last 4 months revisiting my earlier submission of Krusty's Super Fun House.
One thing that I have noticed, is that this game is like chess. After I sat down and studied the reasons that make this game faster...I realized that I had a flawed approach.
Even though I have currently cut 5149 frames from my original submission, I am still on the hunt for more frames.
Here are some details that I believe will explain my latest findings:
1. When rats are in close quarters, getting a single rat in the chamber as fast as possible is top priority.
2. When rats are spread across widely enough that the cycle of the death chamber can complete before the next rat enters, gives indication on where to focus attention. What I mean by this is, that some rats may be in a line where some are 1 block from each other while others are several blocks apart. You want to focus on how to manage the tighter group, without ignoring the advantage of the first rat being ahead.
3. You have to eliminate all falls and climbs, as much as possible. Even a rat going over one block wastes 16 frames.
4. Sometimes the last rat is a focus, when having to deal with many rats at a time. For example, if there is a lot of chaos trying to set up a pathway for many rats...you have to take in consideration how it will affect the ending rat. There are times when too much going on can hurt the time is takes to have a last rat make it in time. One particular spot...I have to slow down a number of rats in order to "clump" them together to make it faster.
5. The Death chamber entrances are superficial....meaning, if you have a rat enter one of the bottom entrances, it is no different than if you "Fan" a rat over into the top part of the chamber. It is basically, one big hit box.
6 The death chamber operates on an 8 frame rule. If you end up getting back to the door before the rats are finished, then cutting up to 7 frames may not give you an advantage...depending on if you hit the 8 frame rule on the very first part.
7. Krusty's jumping acceleration is maintained longer, if you hold the jump button longer. This goes without saying, but I bring this up to demonstrate an important fact. If you are in tight quarters, jumping longer can help you "Clear" obstacles faster.
8. Krusty has an acceleration address that builds up to indicate how fast his movement is, in terms of horizontal speed. When in tight quarters (where you cannot move left or right), you can press the opposite direction for one frame and then press forward to get this value incrementing faster. In a turn (which is that tight), the value is not reset...giving you a frame or two advantage. One thing to note, you have to be facing in the forward direction for this to work. {NOTHING}, FORWARD, BACK, FORWARD is the inputs that you want.
I'm also currently glitch hunting. It is sad that the only glitch that I've run across is clipping. But it is very limited. In fact, it is use only a couple of places to help create a route that is more efficient. In fact, one particular spot helped to cut around 8 seconds. But there are no floors to be clipping that will make a difference.
How clipping works in this game. If you are about to place a block down AND you have 1 block of space above you, then you can place the block down at the point when Krusty either passes from the 8th to 9th pixel or 9th to 8th pixel...depending on your direction. Once executed, you will get pushed into a block that would have normally kept you from moving. The problem is, you can't move up, if another block is above you. You can't move left or right, if blocks are next to you. So, you can clip a floor in this manner:
https://www.youtube.com/watch?v=8Y9xuUGExCM
I expect to still find more frames, but it is becoming more painful to find them. If I can't find a frame after a month's worth of trying, then I will go back to fill in the "Dead" space and make my final submission (I hope the final).
This newer version is much more active and also doesn't sit around the door as much. I would say that about 20% of the door twitching time has been removed. :)