Pan Roast Pheasant fillet with Apples & Cider

Since game is widely available during fall/winter in England, I thought I would try to cook it by myself. I had bought partridge fillets online but it was out of stock on the delivery day. Our delivery man kindly brought a thoughtful substitute to us: pheasant fillets. I simply accepted it. I probably wouldn't know the difference between two birds since both were equally unknown to me. Plus, there wasn't any specific reason why I chose partridge over pheasant when I made the order. I would try pheasant eventually anyway.

I searched a recipe for partridge fillets online and found one that sounded nice - Pan-roasted fillets served with Dijon mustard-y cider sauce, apple and spinach, garnished with fresh thyme. For starch, I was going to add mashed potato. I applied the plan to my pheasant. 

The result looked lovely but sadly the pheasant fillets were very dry. Did I cook them too long? By the way, their taste was somewhere between chicken and duck, I thought. 

My favorite parts of the dish were sautéed apple and hidden spinach. Should I try it again to make it better? Perhaps, try with pheasant? Well, now my interest in game is kinda over...