Ok, using the Toymallet rules are simplicity itself.
Our niece is spending the weekend with us and tonight was games night. After a couple of games of Cranium, I left my 13 y.o. son in charge of running a Toymallet game with his sister and younger niece.
I came back about 30 minutes later to find the Tyranids and Space Marines, supported by Ironman, engaged in wiping out a platoon of Imperial Stormtroopers.
Fun was had all around.