Submission #2818: nitsuja, upthorn, marzojr's Genesis Sonic 3 & Knuckles in 31:33.52

Console Sega Genesis Emulator GENS
Game Version any Frame Count 113611
ROM Filename Sonic and Knuckles & Sonic 3 (W) [!].bin Frame Rate 60
Branch Rerecord Count 204460
Unknown Authors nitsuja, upthorn, marzojr
Game Sonic 3 & Knuckles
Submitted by marzojr on 8/28/2010 12:10:27 AM

Submission Comments
Yet another chapter in the Sonic 3 & Knuckles saga, featuring two more improvements which combine to reduce the run time by 2309 frames, or 38 seconds and 29 frames.

Game objectives

  • Emulator used: Gens 11a + S3KCamhack + SolidityViewer + (partial)HitboxDisplay + LUA HUD for Genesis Sonic games
  • Ignores delays caused by bonus effects
  • Aims for fastest (primarily in-game) time
  • Takes Damage to save time
  • Abuses death
  • Abuses programming errors
  • Counts time spent dying
  • One player controls two characters


Two levels have been improved from the previous version: one due to a new glitch, the other due to improved precision in a boss fight.
There are 21 frames worth of luck-manipulating pauses in Sky Sanctuary: 5 at the beginning and 16 at the end. The 5 frames at the beginning of that level are to manipulate the Mecha Sonic pattern; without it, more than 20 frames would be lost at the boss fight. The other 16 frames these are intended to put the Death Egg 1 mini-boss in a more favorable pattern.

Comparison Table

ActNew TimeOld TimeSavings
Launch Base 20:26::581:04::562278
Post Launch Base cutscene 20:18::060:17::53-13
Hidden Palace0:18::260:19::1044
Total savings: 2309 frames (38 seconds and 29 frames) in in-game time.
The table shows the in-game timer values. The value after the final colon pair indicates the in-game frame counter, and is restricted to the 0-59 range. It is updated every frame (except during lag frames), and increments the in-game second when resetting to zero.

Stage by stage comments

Launch Base 2

A few minutes after the submission had been accepted for publication, Mr_Sweed sent me a video showing an improvement of 10 seconds for Launch Base 2 over the submission, and about 32 seconds faster than the previous run; that improvement turned out to be suboptimal by about 5 seconds. Splicing the improvement made the following cutscene longer by 13 frames, and nothing I did made any difference.

Hidden Palace

This features a 44-improvement on the fight versus Knuckles. I only had the idea for this improvement after the previous run was already published, sadly. This improvement first debuted in the newgame+ run.

Other comments

For more comments about the run, see the comments from the previous run, as well as the runs that it obsoletes.
Thanks goes to Nitsuja and Upthorn for their Sonic runs, Orkal for his glitch videos, to Mr_Sweed for the Launch Base 2 improvement and to you for watching.

Possible Improvements

In Marble Garden 2, there is one of Robotnik's attack patterns which allows a 1 frame improvement; it takes much longer to manipulate it (with pauses or by loitering) than it is worth, unless one were to gain enough frames in the preceding levels to manipulate this attack pattern (not an easy task).
The pauses at the start of Sky Sanctuary may be removed if enough frames are gained in the preceding levels. As is, all of the boss attack patterns cost about 20 frames with perfect play in in-game time. Those 5 frames would be a real-time improvement only.
Likewise, if one were to replay the Death Egg 1 boss, up to 16 frames in real time (but none in in-game time) might be saved by removing the pauses at the end of Sky Sanctuary. However, most of the boss attack patterns in that range are highly unfavorable and probably slower to kill; in all likelihood, at most about 6 frames of pauses might be gained by replaying the fight. Again, this would only be a gain in real time; in in-game time, no frames can be gained from this.
With the same input and the same position (right down to the same subpixel position), the death at the start of Hydrocity 2 can be 1 frame faster -- Sonic even dies at the same frame, but the timer stops 1 frame earlier. Likewise, the post-Launch Base 2 cutscene can be 15 frames faster by standing in the same exact position. I don't know what causes these differences, but it is probably related to cumulative differences in execution, as they usually occur when the preceding levels have changed in length (up or down). If one were to gain "enough" frames in the preceding levels (again, not an easy task), these "extra" frames might simply just go away; I have no idea what would constitute "enough" frames for this to happen, though.
I am not aware of any other improvements at this time.

marzojr: Canceling to look for improvements

Last Edited by TASVideoAgent on 8/18/2012 9:06 PM
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