3 Heads of Fortune

A Collection Meter is a system where a progress bar or gauge (meter) is present on the game screen, which fills up each time the player collects specific symbols or performs certain actions. The core of this feature is to provide the player with a long-term goal that goes beyond the success/failure of a single spin. When the meter is full, an instant prize or a special bonus is awarded as a reward. This provides players with a growth-type fun, similar to 'leveling up' or 'completing a quest'.

Reel Expansion is a feature where the physical size of the game grid (reels or rows) actually gets bigger, typically upon entering a bonus round like free spins. This goes beyond simply adding a multiplier; it aims to expand the 'board' of the game itself, providing players with a wider field of opportunity and fundamentally increasing the number of winning ways.