You can turn on/off the Super Stake feature between base game spins, and switching it on doubles your normal bet size per spin. What you get however, is the possibility of multiplier symbols in the base game. These land with values between x2 to x100, and boost any win that is present at the same time. Multiple multiplier symbols will be added together, and they can appear in PopWin sequences too.
You win by landing matching symbols from the uttermost left to right, and vice versa, and the symbols pay between 1x and 12.5x your stake for 5 of a kind wins. Each win triggers the PopWins mechanic, which doubles the amount of positions involved in a win. The new positions get filled with random symbols, and this process can repeat until the 5x3 grid with 486 default win ways expands to 5x6 with 15,552 ways to win. The grid resets between paid spins.
Maxing out the base game grid triggers the Bonus Round, and a wheel will then spin to award between 8 and 15 free spins with a x2 to x25 starting multiplier. The 5x6 grid is default in the bonus round, but you can increase the reset grid size by getting all rows to the same level in a single spin PopWin sequence. The win multiplier increases by +1 per popwin, or +2 if you manage to max out the default grid to size 5x9.
The Bonus Buy option is available in some jurisdictions, but not in the Ireland for sure. You get 15 free spins from all 3 options, and here’s an overview: