Hi, your luck is:

35% cashback on losses up to 25 mbtc on any of the following slot games: 4 Seasons, Weekend in Vegas, Event Horizon and Viking Voyage.
T&C: the bonus awards back 35% of any losses generated on the games indicated above, up to 25 mbtc. Only losses that are generated until  00:00 Thursday UTC will be taken into account for the current promotion. The cashback will be credited the following day. The cashback will be awarded as a bonus cash with a rollover of 40 and can be used only on  4 Seasons, Weekend in Vegas, Event Horizon and Viking Voyage.