diff --git a/crates/wasm-actor/tests/wasm_actor.rs b/crates/wasm-actor/tests/wasm_actor.rs
index 524e418..ad5eaea 100644
--- a/crates/wasm-actor/tests/wasm_actor.rs
+++ b/crates/wasm-actor/tests/wasm_actor.rs
@@ -10088,4 +10088,127 @@ fn echo_with_address_only_no_payload() {
     // Echo should send back empty payload
     let resp = inbox.try_recv().expect("echo with 0-byte payload");
     assert!(resp.0.is_empty());
+}
+
+// ── Cycle 69 ─────────────────────────────────────────────────────────────────
+
+// Guest with multiple globals — verifies complex state management
+#[test]
+fn guest_with_multiple_mutable_globals() {
+    let wat = r#"(module
+        (memory (export "memory") 1)
+        (global $a (mut i32) (i32.const 0))
+        (global $b (mut i32) (i32.const 100))
+        (global $c (mut i32) (i32.const 200))
+        (func (export "alloc") (param $len i32) (result i32) i32.const 1024)
+        (func (export "handle") (param $ptr i32) (param $len i32)
+            ;; Rotate: a=b, b=c, c=a+1
+            (local $old_a i32)
+            (local.set $old_a (global.get $a))
+            (global.set $a (global.get $b))
+            (global.set $b (global.get $c))
+            (global.set $c (i32.add (local.get $old_a) (i32.const 1)))
+        )
+    )"#;
+    let engine = SharedEngine::new().unwrap();
+    let actor = WasmActorBuilder::new(engine, wat::parse_str(wat).unwrap())
+        .build().unwrap();
+    let rt = Runtime::new(RuntimeConfig::default());
+    let addr = rt.spawn(actor).unwrap();
+
+    // Send 10 messages — complex state rotation
+    for _ in 0..10 {
+        rt.send_to(addr, ByteMessage(vec![0])).unwrap();
+    }
+    rt.tick(); // no trap
+}
+
+// Builder with very large WASM module (100KB of data segment)
+#[test]
+fn large_data_segment_module() {
+    // Module with a large data segment (4KB of zeros)
+    let mut wat = String::from(r#"(module
+        (memory (export "memory") 2)
+        (data (i32.const 0) ""#);
+    // Add 4096 escaped null bytes
+    for _ in 0..4096 {
+        wat.push_str("\\00");
+    }
+    wat.push_str(r#"")
+        (func (export "alloc") (param $len i32) (result i32) i32.const 65536)
+        (func (export "handle") (param $ptr i32) (param $len i32))
+    )"#);
+    let engine = SharedEngine::new().unwrap();
+    let actor = WasmActorBuilder::new(engine, wat::parse_str(&wat).unwrap())
+        .build().unwrap();
+    let rt = Runtime::new(RuntimeConfig::default());
+    let addr = rt.spawn(actor).unwrap();
+    rt.send_to(addr, ByteMessage(vec![1; 100])).unwrap();
+    rt.tick();
+}
+
+// Echo then double from same engine in same tick — interleaved processing
+#[test]
+fn echo_and_double_interleaved_in_same_tick() {
+    let engine = SharedEngine::new().unwrap();
+    let echo = WasmActorBuilder::new(engine.clone(), guest_wasm("echo")).build().unwrap();
+    let double = WasmActorBuilder::new(engine, guest_wasm("double")).build().unwrap();
+    let rt = Runtime::new(RuntimeConfig::default());
+    let inbox = rt.new_inbox::<ByteMessage>().unwrap();
+
+    let e_addr = rt.spawn(echo).unwrap();
+    let d_addr = rt.spawn(double).unwrap();
+
+    // Alternate: echo, double, echo, double
+    for i in 0..4u8 {
+        let addr = if i % 2 == 0 { e_addr } else { d_addr };
+        rt.send_to(addr, framed_msg(inbox.addr(), &[i])).unwrap();
+    }
+    rt.tick();
+
+    let msgs: Vec<Vec<u8>> = std::iter::from_fn(|| inbox.try_recv().map(|m| m.0)).collect();
+    // Echo: 2 msgs (1 response each) + Double: 2 msgs (2 responses each) = 6
+    assert_eq!(msgs.len(), 6);
+}
+
+// Guest that stores i64 value (8-byte store)
+#[test]
+fn guest_stores_i64_value() {
+    let wat = r#"(module
+        (memory (export "memory") 1)
+        (func (export "alloc") (param $len i32) (result i32) i32.const 1024)
+        (func (export "handle") (param $ptr i32) (param $len i32)
+            ;; Store 8-byte i64 at ptr (if len >= 8)
+            (if (i32.ge_u (local.get $len) (i32.const 8))
+                (then
+                    (i64.store (local.get $ptr) (i64.const 0x0102030405060708))
+                )
+            )
+        )
+    )"#;
+    let engine = SharedEngine::new().unwrap();
+    let actor = WasmActorBuilder::new(engine, wat::parse_str(wat).unwrap())
+        .build().unwrap();
+    let rt = Runtime::new(RuntimeConfig::default());
+    let addr = rt.spawn(actor).unwrap();
+    rt.send_to(addr, ByteMessage(vec![0u8; 8])).unwrap();
+    rt.tick();
+}
+
+// Runtime dropped while actors are processing — no crash
+#[test]
+fn runtime_dropped_with_active_wasm_actors() {
+    let engine = SharedEngine::new().unwrap();
+    {
+        let rt = Runtime::new(RuntimeConfig::default());
+        for _ in 0..5 {
+            let actor = WasmActorBuilder::new(engine.clone(), guest_wasm("echo"))
+                .build().unwrap();
+            let addr = rt.spawn(actor).unwrap();
+            rt.send_to(addr, ByteMessage(vec![1, 2, 3])).unwrap();
+        }
+        rt.tick();
+        // rt dropped here with live actors and unprocessed responses
+    }
+    // No panic — wasmtime Store cleanup is safe
 }
\ No newline at end of file