Playability: I thought this scenario was pretty fun, at least it held my interest throughout. I can't say I'll play it again, but it was worth the download.
Balance: The scenario was a little on the easy side set at moderate difficulty. All of your 'enemies' kept a neutral stance until the end and then at the end they didn't try hard enough to stop you from completing your final task. This aspect of the scenario was about equal to a random game at the easy setting.
Creativity: While there wasn't anything new about the scenario, basically you just go around finding objects and moving them somewhere else. I thought the reasons for doing so were good.
Map Design: The design was good, but not great. There was some nice use of elevation, and some eyecandy, but not really enough to make it truly pleasing to the visual sense.
Story/Instructions: The intro instructions and history were also good. They gave some nice background on the story and reasons for playing. The in-game instructions were not quite as good but acceptable until near the end. When you find and pick up the final relic you are told to take it to the "Mount of the Shrine" but you're given no indication of where that might be. I tried a few locations before finally loading up the editor to find out where to go. This is immediately followed by another task to "Complete the Great Plan" but again you are not told what the great plan is. An unfortunate end to an otherwise fine scenario.
Final Comments: If it weren't for the apparent oversights toward the end, The Lost Civilization would be a good, solid RPS. I look forward to seeing more from the author.