Submission #2140: marzojr's Genesis Tails in Sonic The Hedgehog in 14:29.30

Sega Genesis
Gens 9z
Submitted by marzojr on 11/20/2008 3:31:47 AM
Submission Comments
Having the powers of flight and spindashing, Tails blasts through Sonic 1, leaving Sonic and even the mighty Knuckles eating dust in almost all levels of the game. This movie was made with Pu7o's Tails in Sonic 1 hack, version 2.1.1.

Game objectives

  • Emulator used: Gens 9Z
  • Aims for fastest time
  • Takes no damage
  • Abuses programming errors
  • Ignores delays caused by bonus effects


This impressive hack by Pu7o places Tails into Sonic the Hedgehog 1. Being a marked improvement (and complete rewrite) over the earlier version by drx, it underwent two revisions during the making of this movie to make Tails' flight and swimming work exactly like they do in Sonic 3 and Sonic 3 & Knuckles.
This was based on the Sonic and the Knuckles runs of Sonic 1. But differences between Tails and Sonic (spindash, flight and even hitbox size) and between Tails and Knuckles (flight vs. glide/climb) made some routes impossible while enabling others. Overall, the two-tailed game wrecker blasts through the game leaving everyone else far behind.
The biggest time saver was the abuse of the Sonic 3 enforced screen boundary for Tails' flight: whenever you start flight (or boost) at or above the top of the stage, vertical speed is set to zero, preventing horizontal speed loss due to drag. Thus, you can maintain a given altitude and horizontal speed for as long as Tails' can fly. The use of this technique is marked below.


Green Hill 10:16:34
Green Hill 20:15:15
Green Hill 30:28:25
Marble 10:13:23
Marble 20:14:19
Marble 30:27:08
Spring Yard 10:18:41
Spring Yard 20:15:38
Spring Yard 30:38:49
Labyrinth 10:24:39
Labyrinth 20:24:08
Labyrinth 30:27:08
Star Light 10:17:19
Star Light 20:10:11
Star Light 30:29:27
Scrap Brain 10:21:22
Scrap Brain 20:19:13
Scrap Brain 30:08:45
The table shows the in-game timer values. The value after the final colon 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

Green Hill Zone 1

The flight and subsequent braking at around 0:09 avoid losing some time to jumping, and manipulate the position enough to make the most of the triple-jump boost at the loop and allow a bugged vertical speed drop after the tube which saves me some 4 frames of drag around 0:13:56. That flight is above spindash speed, and that speed is kept until the end.

Green Hill Zone 2

Alas, the ease with which Tails could enter the wall even for casual players at the start of this stage means Pu7o added some extra walls to prevent it. Thus, Tails has to go through by sheer speed. This is one of 3 levels in which Knuckles is faster than Tails, and the only level in which Sonic is faster than Tails.

Green Hill Zone 3

Same route as Knuckles. Some bits of flight here and there make Tails slightly faster.

Marble Zone 1

Same basic route as Knuckles, as using the cave zip from the Sonic run is slower. Using flight at 0:04:48 allows me to reach the slope at 0:06:44 with tremendous horizontal speed, resulting in a very high vertical speed. Pixel/subpixel manipulation allows me to hit the slope at 0:12:28 in very favorable conditions for that last jump.

Marble Zone 2

Same basic route as Knuckles, as the Sonic route is much, much slower. Abusing slope, Tails can fly to the top of the walls with minimal speed loss and without having to bounce on the bees. Letting go of the spindash even a frame before 0:07:35 hits the wall and stops; immediately after, subpixel manipulation allows me to hit the ground at an optimal slope change to fly up the wall.

Marble Zone 3

Same basic route as Knuckles, as using the cave zip from the Sonic run is slower. Delaying flight at the start results in a very large speed gain. I have to jump/brake at the top of the wall for the second spindash to avoid losing time. Some braking after the ground is done allows me to abuse slope when I hit the ground below and set up another optimal slope change at the final slope before the boss. The boss is killed perfectly: Robotnik can't be defeated even a frame earlier.

Spring Yard Zone 1

Starts more or less the same way as Knuckles, but uses the Sonic trick when getting the speed shoes (Knuckles can stop with glide there). I avoid rolling down the slope at around 0:07:00 to retain control when I jump 12 frames later; this allows me to lose less speed due to drag because of the enforced screen boundary abuse.

Spring Yard Zone 2

With some (massive) improvements courtesy of Upthorn, this level abuses the enforced screen boundaries only slightly: at the beginning, to keep most of the speed up until that big slope which I roll down. Slope jumping and abuse of changing slope lead to insane speeds for the rest of the level.

Spring Yard Zone 3

Sadly, Tails can't fly above the wall because of the enforced screen boundaries. It is also impossible to reach those moving sprites at 0:05:xx fast enough to not have to wait. Tails isn't fazed, and abuses the enforced screen boundaries to end the level very quickly. Even taking the speed shoes as Knuckles and Sonic do isn't enough to compete with Tails here. Flight saves the day further by allowing Tails to defeat the boss ultra fast. This level has some improvements by Upthorn, and is the only level other than the Final Zone to take more than 30 seconds.

Labyrinth Zone 1

Not much to say. Knuckles can use glide to great effect in this stage, saving about 1.5 seconds over Tails due to not having to wait as long to reach the ground after the several jumps.

Labyrinth Zone 2

A better start, and the shortcut from the Sonic run allow Tails to do this level faster than Sonic or Knuckles. This level has some improvements by Upthorn.

Labyrinth Zone 3

Swimming allows Tails to reproduce the shortcut used by Knuckles. It also allows Tails to enter the shortcut more efficiently, and to improve it markedly by not having to wait for the screen to catch up.

Star Light Zone 1

Flight allows me to touch the bridge a few frames earlier. Subpixel manipulation at the wall at 0:03:24 to 0:03:47 allow me to gain great speed by jumping at 0:06:54 and slope jumping afterward and still clip the edge at 0:07:36, allowing me to reach the ledge without using flight or the spring. Slope jumping and flight give me a high speed at the end.

Star Light Zone 2

Spindash and slope jumping give me some insane speeds to work with. Add in the enforced screen boundary abuse to keep most of the speed. The result: I have to do some braking at the end of the level so that the screen can catch up enough that I hit the end sign.

Star Light Zone 3

Slope jumping, enforced screen boundary abuse and subpixel manipulation (about 0:12:00 to 0:12:20) afford some insane speeds. Flight then allows me to slaughter Robotnik.

Scrap Brain Zone 1

Following the Knuckles route, as the Sonic route ends up being slower. Flight makes this route much more effective.

Scrap Brain Zone 2

Running through the fire at the beginning allow me to hit the gear in a way that I can gain absurd vertical speed in that jump. I use the Sonic shortcut, but improve it with judicious spindashing. At around 0:11:xx, I could brake faster or release the spindash earlier; but I would just bump into the saw and lose a lot more time than I do waiting a little bit. I then abuse the changing slopes and fly until the end. Stage transition is very optimized too.

Scrap Brain Zone 3

Using spindash and flight to improve on the shortcut from the Sonic run gives an insanely short time for this stage.

Final Zone

This is a single frame slower than the Knuckles version of the stage. I can't figure out where this frame is coming...

Other comments

I wish to send a big thanks to Upthorn: not only for several extremely useful suggestions for improvements, but also for actually improving 3 levels and for making a special version of Gens with camera hack for this ROM.
Possible improvements: It might be possible to improve Green Hill Zone 3 by one or two frames up until the boss, and maybe by another frame in the boss fight. Labyrinth Zone 1 might also be improvable by some 2 frames. And I think that it may be possible to gain a couple frames in the boss fight of Star Light Zone 3. I have tried to make these improvements in many different ways, but always ended up failing, though.
Suggested screenshot:

NesVideoAgent: Hi! I am a robot. I took a few screenshots of this movie and placed them here. I'm not sure I got the right ROM though. (I tried Sonic Spinball (U) [p1].gen, which was the closest match to what you wrote.) Well, here goes! Feel free to clean up the list.

mmbossman: I am rejecting this submission because it is extremely similar to the Knuckles hack of Sonic 1 that is already published, with a detailed breakdown here. Although this run is both well done and entertaining, it is lacking in unique content, due to the fact that spin-dashing is identical, and flying is only minimally different than gliding. Best of luck on your next project, marzojr, you have some good TASing skills, so please take this decision as constructive criticism.

mmbossman: This submission has been given another chance at publication. If you feel it should be published, instead of returning to the grue, please post WHY in the thread. Similarly, if you do NOT think this movie should be published, post WHY.

mmbossman: People really like this run, so I'm reverting my previous decision. Accepting as a new run, to be placed in 'Concept/Demos' (at least for now).

ShinyDoofy: Will publish "soon".
Last Edited by adelikat on 9/15/2023 3:14 AM
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