The Spike DX is a DLC that gives you some extra features.

• You can play all stages in different player positions.
• Instantly acquire 2000 Volleyballs.
• The amount of Volleyball you receive as a gameplay reward is doubled.

※ "Volleyball" is a name of the in-game currency.

As the elements to be added are mainly focused on in-game currency boosts, so it would be good to think of sponsoring developers and getting small rewards in return.

In addition, if you purchase this DLC you will immediately receive some in-game currency, so please note that refunds are not possible according to the Steam Refund Policy.

Have a nice weekend.

Thank you.