I've asked in Kaboo casino why I can't play Tower Quest (the error message was saying I have insufficient funds even though I had funds) and they gave the following explanation:
The balance I had was from a deposit + bonus and still under wagering restrictions.
When asked why, they simply stated it was decided by the Bonus Team and then closed the chat.
In the addition to the above I was also unable to play Eye of the Kraken game, I suspect for the same reasons.