Haha yes! After the initial waves (where I had to put a tower just when reaching 11secs in order to survive), it becomes easier. Sometimes enemies appear very close to the edge at the beginning of waves (bug?), this made me lose a few times! :)
But after that it is possible to spam turrets as you get a lot of time, and that's when you become the Time (edge) Lord I guess!
As for the audio I guess it is really hard to make it work well, especially considering the number of enemies on screen (if they all are sources for sounds).