General guidlines for building:

-Try to keep the number of level polygons in view at a time to around 1500-2000. This will ensure that the level can be played on minimum spec machines. Depending on the situation, some levels can have more than that ( you will find that some of the RS levels will go to 2000-3000) but be careful and try out your level before releasing it. 

-Try to keep the # of portals to less than 7 if possible. This is not a requirement, but the more portals in view the game has to calculate more and thus start to slow down.

