Golden Fish Tank is a 2017 Yggdrasil release that takes the humble aquarium as its setting and makes more of it than the premise might suggest. The tank decoration upgrade mechanic — where base game play gradually improves the bonus features for subsequent rounds — gives it a layer of progression that makes the base game meaningful rather than just a waiting room for the Free Spins.

The game runs on a 5-reel, 20-payline structure. Bets go from €0.10 to €100 per spin. The aquarium aesthetic is colourful and warm — tropical fish, bubbles, coral, and the gentle visual language of a well-kept tank. It is an easygoing setting that suits the medium volatility profile.

Fish wild multipliers are the central feature of the Free Spins round, with individual fish wilds carrying multiplier values between 1x and 5x. Multiple wilds on the same spin stack their multipliers, creating the potential for combined multiplier values when several fish wilds land together. In the base game, tank decoration upgrades accumulate as certain symbols land, with fully upgraded tanks unlocking bonus awards — the progression system that gives the base game its extra dimension.

RTP is 96.29% with medium volatility. Maximum win is 500x the stake. Medium volatility and a 500x ceiling describe a session profile of reasonably consistent returns with moderate peaks — the fish wild multiplier stacking provides the upper end of that range.

Golden Fish Tank is a well-balanced medium-volatility slot with a progression element that rewards attentive base game play. The fish wild multipliers give the Free Spins genuine upside within the medium-volatility framework. Suits players looking for an engaging session without high-volatility swings.