What you don't see are the failed attempts at various stages that I cut out. As you will see in the video I quick saved a bit. Portal walkthrough for /īonus Map Test Chamber 18 'Advanced' using computer tower hack. Portal - Bonus Maps - Test Chamber 18 (Advanced).Most of the test chambers have multiple solutions, so what's shown here is only one way of completing them. As usual, I go pretty fast most of the time and I take a few shortcuts here and there. Welcome to the Portal advanced test chambers! These are not part of the main campaign but I've also recorded them for your viewing pleasure. Portal - Bonus Map: Test Chamber 18 Advanced.Related Portal Bonus Maps Test Chamber 18 Advanced Its not a step by step guide or anything just a video that gives you the. This is for those who are having trouble with the Test chamber 18 Advanced level.