1. your video demo's music is way too loud. blasted my apartment in the early morning and added nothing to the demo. i'd take a shitty loom video with your narration saying whats happening over this.
2. you'll have to overcome quite a lot of skepticism that this works beyond an initial demo. your video shows a very standard greenfield setup that doesnt really need AI to do. how does it handle more interesting change requests of an existing app? how does it handle fullstack changes? how does it handle design? if you could include sample output (or links to generated diffs) on your landing page you might start to deal with that cynicism.
3. how are you thinking about defensibility? if this works it can be easily copied.
4. beyond this, the business model challenge i would fear for you is this is really a use-once-and-done tool. 299/mo is not really high enough to sustain a biz for that. i guess you're very focused on making it a recurring need but you have your work cut out for you. good luck.