So I have come to the conclusion that
Wuhu Island should not be legal. This is on the basis that the stage is
too large.
I have played on the stage plenty of times now, and while I had the inclination that the stage was too big, posts like this one...
Wuhu's blastzones are actually fairly average, for the most part. The ceiling is extremely mundane, at least during most segments; the blastzones to the left and right of the stage are only large when you factor in its overall length. From my experience, people don't live that much longer there. Sure, it's kind of slow and campy, but is that really a reason to ban a stage? Why?
...prompted me to test it objectively, otherwise I wouldn't have a factual basis to state otherwise. So, I've done some tests.
I performed three kinds of tests. The first test was to test kill % using Mario's uncharged Forward Smash on another Mario at the edge of the stage (Mario in his tipping animation). The kill counted towards results as long as Mario entered the side blastzone, indicated by a horizontal blast animation, not a diagonal one. The second test was using Mewtwo's up throw on a Mario. Mewtwo was chosen thanks to the up throws straight trajectory, and throws were always performed on the base stage, not a platform. The third test performed was to compare the relative length of the various transformations in Wuhu. This was done by using Captain Falcon's up tilt to travel the length of the stage. Each up tilt counts as 1 unit.
For each of these tests, fixed camera was used, with Mario set to control with no DI used.
Before posting the results, here are some relevant bench marks:
Horizontal Blastzone Kill %'s:
Big Battlefield: 65%
Battlefield: 72%
Smashville: 64%
Final Destination: 65%
Vertical Blastzone Kill %'s:
Big Battlefield: 154%
Battlefield: 141%
Smashville: 133%
Final Destination: 133%
Travel Units:
Big Battlefield: 51 Units (7 Luigi Back Rolls)
Battlefield: 31 Units
Smashville: 28 Units
Final Destination: 34 Units
Big Battlefield was chosen as a bench mark to help illustrate what a large but otherwise legal stage might look like, size wise, while the other three were for comparison against healthy legal stages.
Name|Picture|Notes
Platform 1|
|Horizontal Kill %: 60 Vertical Kill %: 141 Travel Units: 41
Platform 2|
|Horizontal Kill %: 60 Vertical Kill %: 131 Travel Units: 40
Platform 3|
|Horizontal Kill %: 60 Vertical Kill %: 141 Travel Units: 41
Platform 4|
|Horizontal Kill %: 60 Vertical Kill %: 141 Travel Units: 41
Name|Picture|Notes
Arena|
|Horizontal Kill %: 76 Vertical Kill %: 141 Travel Units: 38
Bridge|
|Horizontal Kill %: Walk Off Vertical Kill %: 135 Travel Units: Too Long
Jet Ski Race|
|Horizontal Kill %: 80 Vertical Kill %: 128 Travel Units: 30
Rocks|
|Horizontal Kill %: 78 R, 70 L Vertical Kill %: 155 Travel Units: 32
Boat|
|Horizontal Kill %: 68 L, 66 R Vertical Kill %: 129 Travel Units: 31*
Beach|
|Horizontal Kill %: Walk Off Vertical Kill %: 141 Travel Units: Too Long
Volcano|
|Horizontal Kill %: 52 Vertical Kill %: 148 Travel Units: 18 Each Side
Fountain|
|Horizontal Kill %: Walk Off Vertical Kill %: 142 Travel Units: 27 Each Side
Cliff|
|Horizontal Kill %: 81 Vertical Kill %: 142 Travel Units: 42
So, looking at this, what can we conclude?
All four platform transformations are relatively the same size wise, with the #3 having high platforms and platform #2 having a slightly lower blastzone ceiling. 3/4 of them having the same blastzone height as Battlefield, known for having a relatively high ceiling. While the blastzones at the edge of the platforms is relatively average, the stage platforms are not, boasting 41 units, making it larger than Final Destination, and much larger than Smashville, horizontally. Overall, the relative horizontal size from centre stage to blastzone is likely close to Battlefield. This isn't too bad with the exception of platform #3's open layout, which can make it hard for certain characters to give chase.
Arena is larger than Battlefield, boasting 7 more units of stage space and larger horizontal blastzones. While it shares the same vertical ceiling size, it has no platforms to mitigate this problem for characters that KO vertically.
The Bridge is massive. It's a walk off with tons of horizontal room, and for obvious reasons was not tested for travel units or horizontal kill %. Vertically the ceiling is higher than Final Destination and Smashville. It is not higher than Battlefield, but again, no platforms to supplement the difference.
Jet Ski Race is okay. It's roughly the length of Battlefield, however its horizontal blastzones are deceivingly bigger, killing 8% later than usual. The vertical blastzone is quite low here by comparison. Overall this transformation is okay. Despite the larger sides, the smallness of the main platform makes engaging the opponent easy.
Rocks is very big. It has a higher ceiling than even big Battlefield, and side blastzones almost as large or larger than regular Battlefield depending on which side you're on. This might seem okay with the 31 units of stage space, however this measurement did not account for the water space in the middle, which could not be accurately tested. Overall, it's likely closer to 40+ units. Unnecessarily big transformation.
Boat is fine. Nothing to complain about regarding this transformation.
Beach is stupid. Travel units and horizontal kill %'s not done for obvious reasons.
Volcano boasts high blastzones, killing roughly 7% later than on Battlefield, again with no platforms to supplement the issue. Horizontal kill %'s were low at 52%, but this was done at the bottom platforms, not on the main stage. To add to this, the total ground space covers 34 units total, and like Rocks, does not account for the space in the middle, likely pushing the overall space to 40+ units of room between ledges.
With 27 units of space on either side of the water spout, Fountain has almost 60 units of horizontal stage space. You'd think the ceiling blastzone would be low to compensate, but no. Once again it is equal to Battlefield with no platforms to compensate.
Cliff has 42 units of room before going off screen, making this still a decent bit larger than the three legal stages. The kill zone to the right is much larger, requiring over 80% to land a kill. And once again we have the Battlefield-esque ceiling heights with no platforms.
Basically, the only reasonable parts about Wuhu Island regarding size are platform #1, #2, #4, Boat, and maybe Jet Ski Race. The other 8 transformations are too large given their stage space, layout, ceiling height, and side blastzones. While I would say this stage hurts characters that kill vertically more than horizontally, it isn't nice either way. Most transformations are have heigher ceilings than Battlefield with no platforms, while the relative stage space in units makes landing killing blows mid-stage very unreasonable. Couple this with the fact that 4 out of the 13 transformations have walk offs, and many are susceptible to character match up abuse (i.e. Sonic versus Ganondorf), and this stage has no business being legal in my mind from the sheer size it boasts.
I do think it is an excellent doubles stage.