Crystal Odyssey™

Crystal Odyssey is a slot game with 4 reels and 13 win lines.
10 of the 13 win lines cover 3 positions on the reels, the remaining 3 cover 4 positions allowing 4-of-a-kind wins.
There is a cluster of 3 wild symbols on the 4th (most right) reel.
Wild substitutes for all symbols except scatter.
A Wild-symbol that doesn’t substitute will be held (free hold) for a second chance.
Wins are made up of 3-of-a-kinds or 4-of-a-kinds.

3x scatter pays 10 free games.
4 x scatter pays 20 free games.

During free games a cluster of 3 wild symbols is locked on reel 4, resulting in a high hit during free games because of these wild symbols substituting.
Also, during free games, the Wild-symbol does substitute for the scatter symbol which increases the chance of free games (re-)triggers.