I started using Metroretro a few months ago and it's really nice, except for the ability to export retro items I think it covers everything you listed. Also it's free and it comes with some useful templates. Source: about 3 years ago

To improve the developer experience, I needed to understand the real problems the engineers were facing, so I scheduled a brainstorming meeting. In this meeting, I explained my project and shared a Metro Retro board to write down all issues our application had at that time, what was the bad DX we had, and doubts related to this application (e.g. How do we handle data fetching?; how do we handle error handling?;... - Source: dev.to / over 3 years ago

Let's keep it going :D Writing a Minimum Viable Cartridge for WASM4 (https://wasm4.org/) using WAT: https://twitter.com/warianoguerra/status/1748382204508410149 Wasm compilers in a tweet: https://twitter.com/warianoguerra/status/1576166873296941056. - Source: Hacker News / 5 months ago

You should checkout WASM4⁽¹⁾, an Open Source WebAssembly-based fantasy console with 4 colors and a 160x160 screen. One of its advantages over TIC-80 is that you can program games in any language that compiles to WebAssembly. The games are tiny pure Wasm "carts" that can run on any Wasm runtime, from the browser to Nintendo 3DS. [1] https://wasm4.org. - Source: Hacker News / 9 months ago

I created a showcase (and a Rust crate) which enables to create a random seed in the [wasm4](https://wasm4.org) fantasy console. With this seed a game could create a different map or other game items and events and would enable replaying the game with difference in these game items (if a different seed is chosen). In the wasm4 console (and potentially others) there is no source of random or a random number... Source: over 1 year ago

If you have a simple game idea you want to write, you can use wasm4 (https://wasm4.org). Source: over 1 year ago