The one thing that annoyed me was the music from the pool bar - apparently the guy responsible for operating it has one CD with his favourite songs (mostly pop from 90's) and believes that the louder the better. Over time, this got increasingly annoying - hearing "Don't speak" from No Doubt for the first time was a nice dejavu from 1996, hearing it 10x every day not so much.
Also, I'm a cat person and over the two weeks I spent in Agia Marina I saw a single one. That made me a bit sad :-(
Spent two weeks there, and I was quite pleased. The hotel is nice, clean and cozy and generally close to everything you need (minimarkets, restaurants, beach, ...). The hotel has a nice interior area with pool and grassy playground, shielded from the street. I can't remember anything somehow interrupting my vacation. Also the food (which is one of the reasons why I keep going to Crete for my vacation) was really good - plenty of salads, well cooked lamb, etc. Friendly and helpful staff.