What to do if we had unlimited time for evaluation.
Make lo-fi prototype on paper.
Evalutation without users, Walk through with team to do some homework to remove glaring usability problems before talking to real users.
Perform real-life evaluation. Ride the boat and show lo-fi prototype to potential users asking for feedback.
Improve lo-fi prototype
until no obvious improvements found
Make heuristic evaluation of the refined lofi prototype and improve if necessary.
Make a first prototype using off the shelf hardware and standard software like Unity or Unreal.
Lab evaluation of extremely advanced graphics. Particle animations, advanced wave animations, bird flocks and other eye candy. Does it make any difference in user perception or is it just worthless bells and whistless?