The Castle of Slotenstein — slot review and demo

The doctor's laboratory and three boosters

The slot unfolds in the castle of a mad scientist who created the perfect player — a green monster that cleaned out all the casinos in the area. On 5 reels and 20 paylines, three types of bonus symbols appear: green (Shock), purple (Trick) and blue (Treat). Each activates its own booster in the Hold & Win round. Shock adds a fourth spin instead of three, Trick allows purple symbols to multiply values on the reel, Treat distributes its multiplier to all orange bonuses on the field.

Hold & Win mechanic and Wheel of Fortune

The bonus game starts with one, two or all three boosters — depending on the colours of symbols on the trigger spin. Only bonus symbols with multipliers from 0.5x to 5x bet remain on the reels. Each new symbol resets the spin counter. When a reel is filled with three positions, the values are summed, the reel is cleared, and a Grand Reel of Fortune sector is unlocked. Unlock all five sectors — get a final wheel spin with multipliers up to x8 or one of four jackpots: MINI, MEGA, SUPER, GRAND. The Bonus Buy feature allows you to buy entry with a selected set of boosters.

RTP, volatility and bets

The slot's RTP is 96.02%, volatility is high. Maximum win reaches €234,562. Wild appears on reels 2–5 and substitutes for regular symbols. See the paytable for the full list of multipliers and jackpot conditions.

The Castle of Slotenstein demo

The demo version is available on this page — free, no registration, with virtual credits. It's a convenient way to study how the boosters work and understand how the Grand Reel is assembled. To play for real money in Ukraine, you'll need a casino with a licence from the PlayCity regulator and be aged 21 or over. Bonus conditions and game versions at different casinos can be compared in the online casino rating. Other studio releases are in the Evoplay slots catalogue.