A simple WebAssembly module in Rust draws a bunch of triangles. Try to use GPU-based rendering.
You have to have pre-installed cargo install wasm-bindgen-cli.
To compile wasm do
wasm-pack build --target web
Use miniserve which is installable via Cargo
cargo install miniserve
miniserve . --index "index.html" -p 8080
Open http://0.0.0.0:8080/ on your web-browser.