I've found that not many people are playing my games, either. Granted, the topics and my graphics aren't the greatest, but I was hoping to get a few more plays.
The few Unity games I've gotten to actually run seem to have an issue with taking up a lot of CPU and RAM. It might be that Unity needs more optimizing than other languages/systems. I talked to another dev that their game was using +30% CPU and they were able to get it down to 1-5%, so maybe you can have similar luck. Events, threads, and similar ideas can easily take over a system. You might try putting in some logging to see if something is running when it shouldn't be. Just a thought.