Big Bass Bonanza demo: an old-fashioned machine with one modern trick
Big Bass Bonanza is architecturally conservative. Five reels, three rows, a fixed set of paylines evaluated left to right, and a paytable of the sort that would have been familiar decades ago. There is no tumbling, no cluster geometry, no grid census. A spin lands, the lines are evaluated, and that is the base game. Its reputation does not come from any of that.
It comes from the free spins round, where two symbol types acquire a relationship: money symbols carry a cash value, and the fisherman wild collects every money value on screen when he lands. That collection mechanic is the entire engine of the feature, and it is what turns a plain payline slot into a game people talk about.
The Big Bass Bonanza free play version on this page runs the same logic on virtual credits, and it is a good demo precisely because the mechanic is legible. You can see exactly what has to happen for the round to be worth anything, which is unusually rare in this category.