Game Inside Game

Hello Everyone. Thanks you for being amazing community.

I am a conversion student from Business to Computing. I am doing a MSc project in game development. The feature planned are

1. user can create mini game from provided model and script

2. save and publish them.

3. others can play that game.

4. browser based (online)

I am watching lost of tutorial to be up to date with unity and game development. My plan is to provide models and behaviour(script) in form of Inventory. save and publish game as gem state or prefabs. may be networking to have player account.

My question is how I can or should go about it ? Please put me in right direction. I have 3 months time in hand and ready to do lots of study.

Many Many Thanks in advance.