diff --git a/src/ast/types.rs b/src/ast/types.rs
index 6f180a9..39dd092 100644
--- a/src/ast/types.rs
+++ b/src/ast/types.rs
@@ -204,7 +204,8 @@ impl Record {
     }
 }
 
-pub const UNIT: Expr = Expr::Value(Value::Record(Record(BTreeMap::new())));
+pub const UNIT_VALUE: Value = Value::Record(Record(BTreeMap::new()));
+pub const UNIT: Expr = Expr::Value(UNIT_VALUE);
 
 #[derive(PartialEq, Debug, thiserror::Error)]
 pub enum Error {
diff --git a/src/interpret/interpret.rs b/src/interpret/interpret.rs
index e98e323..b2ca6c5 100644
--- a/src/interpret/interpret.rs
+++ b/src/interpret/interpret.rs
@@ -5,29 +5,44 @@ use std::collections::BTreeMap;
 
 use crate::ast;
 
-pub fn run(
-    program: ast::Program,
+pub fn global_env_name() -> ast::EnvName {
+    ast::EnvName("global".to_string())
+}
+
+pub fn setup(program: ast::Program) -> Result<State, Error> {
+    let mut state = State::new(global_env_name().0.clone());
+
+    defs_to_env(program.0, &global_env_name(), &mut state)?;
+    Ok(state)
+}
+
+pub fn interpret(
+    state: &mut State,
     func: ast::Name,
     args: Vec<ast::Expr>,
 ) -> Result<ast::Value, Error> {
-    let env_name = ast::EnvName("global".to_string());
-    let mut state = State::new("global".into());
-
-    defs_to_env(program.0, &env_name, &mut state)?;
-
-    let main = ast::Expr::Value(state.envs.get(&env_name)?.get(&func)?.clone());
+    let main = ast::Expr::Value(state.envs.get(&global_env_name())?.get(&func)?.clone());
 
     let expr = ast::Expr::FunCall {
         func: Box::new(main),
         args,
     };
 
-    let env: Env = state.envs.get(&env_name)?.clone();
-    let result = eval_expr(&env, &mut state, &expr)?;
+    let env: Env = state.envs.get(&global_env_name())?.clone();
+    let result = eval_expr(&env, state, &expr)?;
 
     Ok(result)
 }
 
+pub fn run(
+    program: ast::Program,
+    func: ast::Name,
+    args: Vec<ast::Expr>,
+) -> Result<ast::Value, Error> {
+    let mut state = setup(program)?;
+    interpret(&mut state, func, args)
+}
+
 enum StatementResult {
     Result(ast::Value),
     Return(ast::Value),
@@ -230,6 +245,33 @@ fn defs_to_env(
     Ok(())
 }
 
+pub fn value_to_stadnalone_expr(state: &State, value: ast::Value) -> Result<ast::Expr, String> {
+    match value {
+        ast::Value::Ref(reference) => {
+            let value = state.variables.get(&reference).clone();
+            value_to_stadnalone_expr(state, value)
+        }
+        ast::Value::Vector(vector) => {
+            let mut vec = Vec::with_capacity(vector.0.len());
+            for reference in vector.0 {
+                let expr = value_to_stadnalone_expr(state, ast::Value::Ref(reference))?;
+                vec.push(expr);
+            }
+            Ok(ast::Expr::Vector(vec))
+        }
+        ast::Value::Record(record) => {
+            let mut map = BTreeMap::new();
+            for (field, reference) in record.0 {
+                let expr = value_to_stadnalone_expr(state, ast::Value::Ref(reference))?;
+                map.insert(field.clone(), expr);
+            }
+            Ok(ast::Expr::Record(map))
+        }
+        ast::Value::Closure { .. } => Err("Closure migration not supported".into()),
+        _ => Ok(ast::Expr::Value(value)),
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/src/interpret/mod.rs b/src/interpret/mod.rs
index a84e1c0..1f1133c 100644
--- a/src/interpret/mod.rs
+++ b/src/interpret/mod.rs
@@ -4,3 +4,4 @@ pub mod interpret;
 pub mod types;
 
 pub use interpret::*;
+pub use types::*;
diff --git a/src/main.rs b/src/main.rs
index 2f03ce0..57d636e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,4 @@
+use ayin::ast;
 use ayin::runtime::*;
 use macroquad::prelude::*;
 
@@ -16,7 +17,7 @@ async fn main() {
     env_logger::init();
     info!("Hello, 👁️‍🗨️!");
 
-    let mut state = setup().await;
+    let mut state = setup(ast::Program(vec![])).await;
 
     loop {
         let events = fetch_events();
diff --git a/src/runtime/runtime.rs b/src/runtime/runtime.rs
index ff4915c..0b61657 100644
--- a/src/runtime/runtime.rs
+++ b/src/runtime/runtime.rs
@@ -1,13 +1,64 @@
 use super::types::*;
 use crate::ast;
+use crate::interpret;
 use macroquad::prelude::*;
 
-pub async fn setup() -> State {
+pub async fn setup(code: ast::Program) -> State {
     let font = load_ttf_font("./assets/fonts/monogram.ttf").await.unwrap();
 
+    let mut state = match interpret::setup(code) {
+        Ok(state) => state,
+        Err(err) => {
+            println!("Error: {}", err);
+            interpret::State::new("game".into())
+        }
+    };
+    let game_state = match interpret::interpret(&mut state, "setup".into(), vec![]) {
+        Ok(result) => result,
+        Err(err) => {
+            println!("Error: {}", err);
+            ast::UNIT_VALUE
+        }
+    };
+
     State {
         assets: Assets { font },
-        code: ast::Program(vec![]),
+        state,
+        game_state,
+    }
+}
+
+pub async fn migrate(mut state: State, code: ast::Program) -> State {
+    match interpret::setup(code) {
+        Err(err) => {
+            println!("Error: {}", err);
+            state
+        }
+        Ok(mut new_program_state) => {
+            match interpret::value_to_stadnalone_expr(&state.state, state.game_state.clone()) {
+                Err(err) => {
+                    println!("Error: {}", err);
+                    state
+                }
+                Ok(expanded_game_state) => {
+                    match interpret::interpret(
+                        &mut new_program_state,
+                        "migrate".into(),
+                        vec![expanded_game_state],
+                    ) {
+                        Err(err) => {
+                            println!("Error: {}", err);
+                            state
+                        }
+                        Ok(result) => {
+                            state.game_state = result;
+                            state.state = new_program_state;
+                            state
+                        }
+                    }
+                }
+            }
+        }
     }
 }
 
diff --git a/src/runtime/types.rs b/src/runtime/types.rs
index 7be8c8c..5706286 100644
--- a/src/runtime/types.rs
+++ b/src/runtime/types.rs
@@ -1,9 +1,11 @@
 use crate::ast;
+use crate::interpret;
 use macroquad::prelude::*;
 
 pub struct State {
     pub assets: Assets,
-    pub code: ast::Program,
+    pub state: interpret::types::State,
+    pub game_state: ast::Value,
 }
 
 pub struct Assets {