Install rustup, then:
rustup update
rustup install nightly
rustup target add wasm32-unknown-unknown --toolchain nightly
rustup component add rustfmt-preview
cargo +nightly install wasm-bindgen-cli
yarn physics:build
cd tiled-utils && yarn && cd -
Tiled map editor is used to generate maps, so you might want to install it if you plan to change maps
cd server && yarn start
cd client && yarn start
yarn physics:watch # watch for rust sources to re-compile physics engine into WebAssembly
yarn maps:watch # watch for maps changes