If you are determined to play on your phone, these are the most common (though unofficial or technical) methods: What's Next After STORM 1 on MOBILE?

: Bandai Namco released the first Storm game as a premium mobile title to gauge interest. While successful, a sequel port has not yet been announced for a standalone release. Alternative Ways to Play on Android

Many "free download" links found online for a Storm 2 APK are often misleading, potentially leading to malware or unofficial fan-made clones rather than the actual game. Official Platforms for Storm 2