add nix flake

flake.lock

@@ -0,0 +1,48 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1740126099,
+        "narHash": "sha256-ozoOtE2hGsqh4XkTJFsrTkNxkRgShxpQxDynaPZUGxk=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "32fb99ba93fea2798be0e997ea331dd78167f814",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "playdate-sdk": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1737690897,
+        "narHash": "sha256-2ii7mcvOEf/oEDuYCnt57zD9Bih/ulFuHj8hAHZU1Ik=",
+        "owner": "RegularTetragon",
+        "repo": "playdate-sdk-flake",
+        "rev": "49528be0b64079d32dbcf50e4e065fa61d9e62bf",
+        "type": "github"
+      },
+      "original": {
+        "owner": "RegularTetragon",
+        "repo": "playdate-sdk-flake",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs",
+        "playdate-sdk": "playdate-sdk"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,24 @@
+{
+  description = "Rush - endless runner for Playdate";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    playdate-sdk = {
+      url = "github:RegularTetragon/playdate-sdk-flake";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = { self, nixpkgs, playdate-sdk }:
+    let system = "x86_64-linux";
+        pkgs = nixpkgs.legacyPackages.${system};
+        playdate-sdk-pkg = playdate-sdk.packages.${system}.default;
+    in {
+      devShell.${system} = with pkgs;
+        mkShell {
+          nativeBuildInputs = [
+            playdate-sdk-pkg
+          ];
+        };
+  };
+}