Only 3 stars because it need more work to be really great, layout is very nice and challenging, there are good tricky corners and good elevation changes.
But there are invisible walls between most of the pitlane and track and here or there outside the track as well as some invisible tree (I guess it was, just hit something hat look like a tree). Colliders seems to have survive your model dissassembly/reassembly process.
Really looking forward new updates. Keep up the good work.