There's always lots of discussion on this topic, and I want to lay out some history as well as clear explanations about POTS style as well as the many derivative styles that sprung forth from it.
PoTS, or Phantom.of.the.Server, was the originator of the style more than a decade ago (Note: would love some information on his actual release history- who came first and who came later) and featured a gameplay style largely reminiscent of Capcom vs. SNK 2. I say reminiscent because in PoTS own words, the majority of the CVS2 similarities came down to "movement." There were some other system mechanics that he implemented as well- but its important to understand that PoTS style itself never followed a set CVS2 groove. Instead, each character developed by PoTS retained a mixture of both various elements of CVS2 as well as various elements from their source games and various appearances.
Each groove in CVS2 represented a system similar to the games represented. In this way, PoTS was able to mix and match aspects of characters gameplay from respective grooves as well as from other games, making them truly representative of all their appearances.
As an example, I will take some PoTS staple mechanics and show you which groove they correspond to in CVS2:
|Dash||C-Groove, A-Groove, P-Groove|
|Run||S-Groove, N-Groove, K-Groove|
|Low Jump||S-Groove, N-Groove, K-Groove|
|Roll||C-Groove, A-Groove, N-Groove|
|Counter||All Grooves except K-Groove|
|Fall Recovery||A-Groove, N-Groove, K-Groove|
It should be noted there is mostly overlap between mechanics arising from the C(apcom) and S(NK) grooves, which bear heavy similarities from those grooves in the original CVS.
In most cases, the above mechanics were standard throughout the publicly available PoTS characters, and form the basis for his style. However, this was not a constant. As mentioned before, PoTS strove to create a custom gameplay mix for each character based on all their appearances, and in many cases skewed their abilities and mechanics closer to what they could do in their source games. The best example is PoTS' Lei-Lei/Hsien-Ko. PoTS attempted to incorporate several Darkstalkers mechanics into Lei-Lei at the cost of other mechanics commonly seen in his other characters. As a result, he implemented the Darkstalkers chain combo system, as well as its cancelling and super cancels. In addition, Lei-Lei loses her power charge. This is actually consistent with CVS2 itself- Morrigan, the Darkstalkers representative, was able to do chain combos in order for players familiar with Darkstalkers to make full use of her. Interestingly enough, PoTS take on Morrigan included the power charges, as well as the "Dark Force" mechanic from Darkstalkers.
All this is to note that there isn't a set, consistent formula to PoTS characters- what was consistent was that he paid very close attention to the source games that these characters came from. He made an effort to understand how they worked and why they did what they did in each game, be it Final Fight or Art of Fighting or supposedly every game Ryu made an appearance in at the time of his creation. He took these aspects and implemented them into a generalized custom environment while still trying to maintain key aspects of game balance- frame data, velocities, recovery, movement, etc.
Because of PoTS own sporadic involvement, there is actually noted difference between older and newer characters from his library, as he began to make more system mechanics standard, and tweaked things. That is to say, it was an actively developing style that responded to feedback and paid the utmost attention to detail. Due to the variance thanks to individual character quirks, PoTS stayed true to CVS2' design philosophy and created a style that could closest approximate what a CVS3 might look like.
Due to the solid play of these characters, they became immensely popular. However, besides a key few aspects, many of these styles are variants on PoTS style with their own gameplay and aesthetic choices. Many are more "standardized" than PoTS actual work, owing to the use of templates or consistent system mechanics. What they mostly share in common is the graphics. PoTS graphics are considered a cleaner version of CVS2's, with fancy hitsparks , super text on finishing moves (using the "badaboom" font style family), and super portraits that flash during the actual move, like so:
Below I will explain some of the major variants and what changes they bring to the table:
Jmorphman can be considered the closest successor to PoTS' original vision, in that he pays close attention to the gameplay elements that have been shared by many of the original PoTS character and has implemented them into his own. Like PoTS, he incorporates various aspects of the characters source material while still attempting to balance them around a generalized custom environment. Many of his characters are indistinguishable in quality from PoTS releases whilst still feeling more modern thanks to advances in coding for MUGEN (particularly in areas like buffering and input.)
The system mechanics I listed further above are shared by most of his characters.
KarmaChameleon bears special mention as a newer creator whos style skews very close to PoTS original visions. Characters like his Genjuro and Blanka pay very close attention to source games and incorporate mechanics from each whilst still using the general PoTS system, making them a good addition to a roster.
Another creator whose characters play extremely close in quality to PoTS.
Another creator whose characters play extremely close in quality to PoTS.
DivineWolf's characters are extremely well known and high quality releases which draw many similarities to PoTS style. However, there are some key differences. The largest deviation is that all of DivineWolf's characters use MAX mode instead of Custom Combo, which is a system derived from SNK games and the N-Groove in CVS2.
Custom Combo was derived from Street Fighter Alpha 2, which when activated allowed faster movement speed and the ability to chain normal and special moves at will with no recoil or charge time. This allowed for lengthy juggles and combos for a short amount of time. In comparison MAX mode gives a flat damage increase, access to changed specials and super, and breaks traditional cancelling rules allowing for fancy combos.
Otherwise, DivineWolf's characters also change depending on source and allow for different types of gameplay styles, including things like Just Defense (originating in garou) and basic air chain combos (such as those in the Marvel Vs. series). He has inspired various authors as well, such as ReddBrink.
Infinite got his start with the "SvK" style, which was a custom style that emulated the fast rushdown aspect of the Marvel series, complete with chain combos and extremely large movesets. Characters had extra system mechanics from the VS. series like air dashes, double jump and access to air blocking. Cancels were far more forgiving.
Infinite's style eventually evolved and was more deeply refined, though the core SvK aspect is still maintained as he has converted many characters with no analogue in CVS like Dr. Doom, Wesker, Taskmaster, Cable, and Deadpool. A config file in many of his later releases in the "Infinite" style now give three system options: one with chain combos, one with chain combos and air combos, and one without. Characters are of varying results due to availability of sprites and frame data, but Infinite offers one of the largest selection of characters that are inspired by PoTS.
Infinite's style is a major influence on its own and there are several creators who use his characters as bases or inspiration for their own further styles, such as Race Akira. Sennou-Room and Falcon Rapper.
Other authors with work very similar to PoTS:
Jesuszilla (Felicia was the only one done in this style to my knowledge.)
These authors were influenced by PoTS style at least in part, but sport different gameplay systems:
I plan to do small overviews later on of these systems.
Badaboom font that is used in PoTS style
Capcom vs. SNK 2 information
Spoiler, click to toggle visibilty