What I meant is that you just export the project as html, then import the files into your project files and display the game from there. Obviously you´ll need a list of your games of some sort and a way to switch between them by simply changing the URL of the iframe.
I noticed that the projects won´t load properly if you import them (because the folder structure isn´t kept on export), unless you exported them as "playable ad" since that only creates a single file. There are some potential issues with this though (it shows a warning about them when you export) But check this out:
wackytoaster.at/parachute/iframeGames.c3p
I think it´s also possible to add them (as a regular html export) later. So you could export your app with the iframe pointing at e.g. glokar/index.html and just copy&paste the glokar project into the exported folder. I didn´t test that though.
And as a third option, since you have them individually uploaded on a website already, you can just load them into the iframe from there. It may require some server settings (CORS) to allow the content to be displayed in an iframe.