Virtual on-screen buttons emulate a standard console controller layout.
Until Bandai Namco finally decides to port the real engine to Android (perhaps via the Unreal Engine 5 mobile branch), the Mugen variant remains the only way to play a "Storm-like" game with a massive roster on your commute to work.
Since Mugen is a lightweight 2D engine, this APK runs well on mid-range and even older Android devices.