The overview of a Windows Installer setup is that files are typically in a CAB file as an embedded resource, and the rest of the setup is a database that contains info about the files, and items I'm going to mention here:
What you not have mentioned about your installer is files that need to go into separate locations (GAC, Common Files, User's Application Data, ProgramFiles etc); data such as registry entries, service install/stop/start, COM registration; how to maintain and upgrade the installed files (the standard is that higher versions override lower versions, updated data files don't get overwritten). Of course there are more things I haven't mentioned (Add/Remove Programs?).
So if you have only a bunch of files (and nothing else) that all go to the same location, and you're not worried about updating it (having no rules about replacing the older files) then your plan might be sufficient for your needs.