That sounds like a fantastic idea! I love playing demos and reporting bugs. A discord also means you can open threads for bug report. I would join.
A game engine sounds really cool. I'd like to hear more about that in posts personally. There's a lot you can do with this and it's great to hear you already have more ideas. A lot of these kinds of games just get abandoned after the first version which is a major bummer. Thank you for your reply!
Edit: I realized that you can also make a feature suggestions channel for your discord, I'll be posting a separate comment for a feature suggestion, lol!