Short answers, pulled from the story.
Street Fighter EX2 arrived in 1998 as a visual paradox wrapping traditional 2D fighting mechanics inside fully rendered 3D character models. The game achieved immediate commercial success with Game Machine listing it as the most successful arcade game of the month in their the 1st of July 1998 issue. A PlayStation port of the game arrived in December 1999.
Street Fighter EX2 was co-produced by Capcom and Arika utilizing the Sony ZN-2 arcade hardware to achieve a level of graphical fidelity that the industry had not seen in the genre. The musical landscape was crafted by a team of former Namco composers including Takayuki Aihara Shinji Hosoe and Ayako Saso.
Street Fighter EX2 introduced Guard Breaks unique moves designed to shatter an opponent's defensive stance and the Super Canceling mechanic which allowed players to cancel a Super Combo into another Super Combo. The most significant addition was the Excel Combo system an abbreviation for extra cancel that enabled players to string together basic and special moves within a limited timeframe.
Street Fighter EX2 features returning legends such as Ryu Ken Chun-Li Zangief and Guile alongside new entrants like Hokuto Doctrine Dark Skullomania and Cracker Jack. The roster also includes four hidden characters Kairi Shadow Geist and Nanase the sister of Hokuto and Kairi who wields a staff alongside Garuda who served as the boss character.
A soundtrack CD for Street Fighter EX2 was released on the 18th of June 1998 by Scitron capturing the energetic themes that accompanied the battles. An additional 13-track arranged album followed on the 23rd of July 1998 released by Suleputer featuring arrangements by the original composers alongside contributions from Yasunori Mitsuda and Toshimichi Isoe.
Street Fighter EX2 achieved immediate commercial success with critics praising the game's graphics and new characters while some reviewers including GameSpot criticized the static ending sequences and the lack of originality in new features. The game was widely regarded as one of the most enhanced and entertaining entries in the Street Fighter franchise despite mixed reviews regarding its incremental improvements over the original.