I stayed at the Stayokay Arnhem for a boardgame event and shared a room with 3 other attendees. The front desk staff were not the most friendly, but the bar staff were very chatty and friendly.
It is certainly a hostel, nothing too flash or fancy and all the fittings are quite basic and rugged, but I guess they need to be.
The hostel serves breakfast and dinner, and there's a supermarket just a few minutes walk away for lunches and snacks. I slept really well each night.
Not the best place to stay if you want to see the town but they have bikes to rent and a few people at the event did that.
