Temple of Thunder II Slot by Evoplay

Mystery symbols are the central mechanic separating base game from free spins. In the main game, these question-mark tiles reveal regular symbols, Wilds, or Coin symbols. Land five or more Coins on a single spin and the Hold&Win bonus activates with 3 respins. Each new Coin resets the counter back to 3. Fill all 15 grid positions and the Epic Prize adds 3,000x on top of every coin value collected.

The four coin tiers carry fixed values: Mini at 10x, Minor at 50x, Major at 500x. Regular coins land with random multipliers of 1x, 2x, 3x, 5x, 9x, 20x, or 25x. During Hold&Win, only coin symbols appear on the reels, so every spin either extends the round or ends it.

Free spins trigger from three scatter symbols on reels 2, 3, and 4, awarding 10 spins with retrigger potential. The key difference during free spins: Mystery symbols reveal only regular symbols and Wilds, never Coins. That strips out the Hold&Win path entirely and shifts the focus to payline wins with Wild substitutions. Three more scatters during the round add another 10 spins.

The Bonus Buy variant of this game adds direct purchase access to free spins, but this version keeps the standard trigger-only format. Without buy bonus, the 3,624x cap sits behind the Hold&Win mechanic, where a full grid of high-value coins plus the Epic Prize delivers the ceiling.