You play with 10 active paylines. You can bet from € 0.02 per payline and therefore from € 0.20 per spin. The maximum bet is €30 per spin. That equates to €3 per payline.
The paytable of Book of Sun is exactly the same as that of Book of Ra. That means that the highest paying symbol is good for up to 5,000 times the stake per payline. On Book of Sun that is not an explorer like Rich Wilde, but a pharaoh.
Horus, the bird's head gamble and known from the Eye of Horus slot machine, pays out up to 2,000 times the stake per payline. The bird and the sacred dung beetle are worth up to 750 times the stake per payline. Playing cards pay out a maximum of 100 or 150 times the stake per payline.
The Book of Sun counts as a Wild symbol. This symbol pays out 'scattered'. To win, the books do not have to be on a payline, nor do they have to be on consecutive reels.
The “gamble feature” after a winning spin is missing on this Book of Sun slot machine from Booongo.

As usual with Book of slots, the Wild Scatter is also the symbol that triggers the bonus. You do this by spinning at least three books in one spin. That gives you 12 bonus spins.
You play these 12 bonus spins with one “Special Expanding Symbol”. During the free spins bonus, this symbol expands if it gives you an (extra) prize.
Except for the Book of Sun, any symbol can be a “Special Expanding Symbol”. For each bonus game, the random number generator determines which symbol is your Special Expanding Symbol.
Winnings can add up nicely in the bonus game if you are awarded a lucrative symbol as a “Special Expanding Symbol” and this symbol actually spins.
For example: the pharaoh as a “Special Expanding Symbol” can give you up to 5,000 times your stake per spin. One copy of this symbol per reel is enough for that.