You must revisit the APK site and manually download the newer build. Uninstall the old version first (backup save data if possible).
Many antivirus tools flag any app not from the Play Store as "Potentially Unwanted Program" (PUP). That does not mean it's malware – but proceed with caution. Download Whack The Serial Killer Apk Android UPD
: Some repositories like FlashStorage.Games offer alpha-version APKs of the original "Serial Killer" chapter for mobile devices. Gameplay Overview You must revisit the APK site and manually