Diamond Monkey

You can depend on Diamond Monkey to always deliver something good if you reach the bonus round, which -I at least- reach quite quickly everytime.
Mostly with three Monkeys on my last free spin, entrusting me with another 10 free spins.
Amatic is amongst the best to grant extra Free spins on top of the ones you started with.

The Money symbol substitutes all symbols.
It only appears on reel 1,3, and 5....which grants 10 Bonus spins (FS)/

At the beginning of the bonus round the expanding symbol is randomly selected (just like any Book of xxx)
That selected symbol pays like the paytable, in all active line (50 winlines), no matter whether the symbols of the winning combination are consecutive or not (again; like any other 'Book of xxx slot out there)
BUT WITH THE EXCEPTION:
The expansion is only downwards.
During expansion the Monkey (scatter) symbol doesn't substitute.
Bonus spins can be re-triggered during the bonus.

The graphics obviously
Amatic slots aren't the most graphically pleasing out there.

The Help section is a tad too lightly filled with info like rtp and such.

From Ancient times, the Monkey was one of the sacred Animals and brought Wealth and Happiness. Particularly, in Eastern countries, Monkeys symbolized different deities. This “Diamond Monkey’’ video slot, coming from Amatic Industries with 5 reels and 50 Paylines. A colourful release with a simplistic gameplay/Medium volatility/Monkey Deity/Multicolored diamond. All represented in this game, Hehe!

The ‘Monkey Deity’ is the Wild and Scatter. You will need at least 3 Monkey symbols, on any position for 10 Free spins. At the beginning of the Free spins mode, the expanding symbol is randomly selected and will pay in all active lines, no matter whether the symbols of the winning combination, are consecutive or not. The mode can be re-triggered!