I should structure the response to first address the unavailability, explain the reasons, warn against unsafe downloads, and then offer legal alternatives. Make sure the tone is helpful and not dismissive. The user might be disappointed, so providing positive alternatives is key to keeping the response constructive.
Also, check if there's any way to access old downloads. If the user previously owned it, maybe on their device, but since app stores remove access, that's not possible now. So, no rescue there.
Also, I should consider alternatives. Maybe recommend trying other music rhythm games that are available now. Games like Guitar Hero Live, Rock Band 4, or even free apps like Osmo or Smule's apps. That way, the user has legal and safe options.
Another angle: Maybe the user is nostalgic and wants to preserve the game. In that case, mentioning archival sites while warning about the legal implications could be necessary. But again, that's not ideal. Focusing on current alternatives is better.
Safety is a big concern here. If the user is looking for a direct download link from third-party sites, they could be exposing their devices to malware or phishing attacks. I should emphasize the importance of avoiding those links. Maybe suggest checking the original app stores if the game is available again, but I don't think it is.
I need to make sure that the user understands that while there might be some links out there, downloading the game through unofficial means is risky and likely against the law. Emphasize legal and safe practices. That's the core of the advice.
Wait, does Rock Band Blitz have any legacy? It's based on real band music but couldn't keep the licenses, so the game was forced to close. That's an important point to mention for context. Users might not know that the game was shut down due to licensing issues, which is a common issue in games that rely on licensed content.
Wait, but how do I explain that it's no longer available? I should check when it was discontinued. Let me think—I remember that Harmonix, the developer, shut it down in 2015 due to licensing issues. So the user might not know that, and they're still looking for a download link, possibly from third-party sites. I need to advise them against that.