Birthday offer 1 is valid for 4 weeks after receiving the email. Offer is valid on game bookings only. Offer is not valid in conjunction with any other offer or discount. Offer is only valid at selected sites (Birmingham, Canterbury, Cardiff, Chelmsford, Ealing, Edinburgh, Exeter, Glasgow, Lakeside, Leeds, Liverpool, Oxford Street, Manchester, Norwich, Plymouth, Southend on Sea, Swindon, The O2, Watford).