The Jackpot Block Party slot machine is part of the Jackpot Party series of slots. You can play this game online for free without having to sign up. The new jackpot slot machine is based on a Las Vegas classic game style. This style of Free to Play Jackpot Slots and Online Casino Games. A free version of the Jackpot Party game that can be found in the Ladbrokes casinos on the High Street. No need to register to play!.