Yes you can, but it may be a little hard going on hot days I would guess about 30 - 40 mins, I'm lazy so I got a scooter
Fortunately Sidari is only about 15-20 minutes further along so instead of walking back go to Sidari, chill out for a while (Sidari is a little like my best friend, great in small controlled doses but I couldn't live with him) and then get a taxi back for about €,14 the taxi rank is right on the main street.
Thomas Cook has all 8 rooms at the Mirage, I went last year and its very very nice and modern, Nikos and Angela are great hosts and make you feel very welcome, the food is also very nice. Quickly checking on the screens the predicted prices are about £250 - £300 per person for a week there (about what I paid), when you book you will be given the fluid price which is affected by demand but 9 times out of 10 it will be cheaper. £300 per person including flights and transfers is good value for that accommodation, early June and late September will have very good prices, October can be expensive, as flight availability becomes an issue. Just noticed we are selling rooms at the Bardis Sun on behalf of Thompson’s, prices are starting at around £480 per person per week, how can they justify that, no reflection on the Bardis, but we sell 1 week Cancun’s for £475?