Had the pleasure of spending 4 nights here recently and couldn't recommend it enough. The apartment is perfect for 2-4 people to spend a couple of days in Agia Marina. Seconds from the beach, it has incredible views of the sea if you wished to have a night in on the balcony. Theres also a great beach club which is a 10 minute walk away called 'Ammos Ilios', we spent most of our time here.
There's a bus which runs into the centre of Chania but we ended up getting taxis most of the time as there only 18 euros. The hosts were great and allowed us to drop off our bags early so we could go off for the day before check in and also booked numerous taxis for us. Couldn't recommend this place enough, we'll definitely be back. Thank you!