Almost all projects do have a promising development. The question is, will they able to keep their promise and follow properly the roadmap on the way? It's hard to determine if the project will be a scam if the developers are active on the way, of course, unless the projects show the common and usual behaviour that they are scams from the start.

I will assume you are an internet guy for a long now so I guess you already know how to spot obvious traits where you can call a project a scam. Now on the part of how to choose legit ones, you really need to enhance your DYOR.