As you're aware, there is 15 XMR up for grabs to the first person who can solve this puzzle. As with all cryptocurrencies, Moneroj are only spendable by those who hold the private key to the public address. That key is a 256 bit number.
The riddles on this (and subsequent pages) provide the clues to unlocking that private key. Once found, you'll be able to import the private key into a Monero wallet and spend the coins.
If you're reasonably new to the inner workings of cryptocurrency, and especially how things like private and public keys work, then even if you don't win the prize, I hope that you find that learning about some of the underpinnings of Bitcoin and Monero is a worthwhile experience. And why these coins are nearly impossible to hack without considerable help :)
Many hunters will know that the answers to the riddles are not arbitrary, but come from a fairly small dictionary. As a twist, I'm not saying which dictionary was used, or how the words will yield the private key (that's part of the fun), but after some sleuthing you'll figure it out.
This reference will give newcomers a pretty good basis for the approach that was used to generate the riddles. Most of the clues are straightforward cryptic crossword-puzzle type clues. Others require some hunting on the internet. Some will need a bit of code.
P.S. Once you have all 24 answers, don't think you can stick them into a BIP-39 online calculator to find the private key. That would be too easy :)
Type your guess here