Return to player
96.83%
Minimum bet
0.10
Game type
Video Slots
Variance
High
Reels
5
Progressive jackpot
No
Popularity
Maximum bet
25
Game provider
Relax Gaming
Bonus features
Yes
Paylines
46.656
Theme
Alcatraz
Hellcatraz online slot game
Hellcatraz is an eighties-style video slot filled with colourful graphics and features. Pick from 2 game modes, uncover mystery symbols, collect rewards through cascading reels, trigger free spins by gathering keys, or use the ‘buy feature’ option to purchase the bonus.
Theme and story line
Hellcatraz draws on the notorious Alcatraz prison for its 80s-style setting. Cops, inmates, and prison guards appear across the reels, which are framed as being on a prison island in the USA.
Graphics, sounds, and animations
Relax Gaming gives Hellcatraz an intentionally eighties look, with fuzzy reels and graphics reminiscent of an old Spectrum computer from the era. The sunset scene looks across San Francisco’s skyline towards the Golden Gate Bridge. US police squad cars provide blaring sirens, while Hellcatraz prison ships bob on the city’s waters. Eighties-style animations and a bubbly theme tune complete the presentation.

Top Casinos to Play Hellcatraz:
Gameplay
Players can choose between 2 modes: ‘Mixed Mystery Symbols’ and ‘Lockdown Mystery Symbols’. Opening the reels presents a 6x6 grid with wins formed through cascading symbols. Behind that layout are 46,656 ways to win.
The objective is to combine any of the 9 regular symbols in groups of 3, 4, 5, or 6. The total spin-bet payouts for placing 6 symbols on a pay line are listed below:
- Prison Guard - 2x
- Inmate - 1.2x
- Shark - 1x
- Guard Badge - 0.8x
- Handcuffs - 0.6x
- Playing Card Suits - 0.4x
A 10th symbol can appear on reels 2-6. This is Hellcatraz’s wild, marked ‘W’, and it substitutes for any of the regular symbols listed above.

Bonuses and free spins
Cascading Reels: Winning symbols burst from the reels before new symbols drop into their places, creating the possibility of further combinations from a single spin.
Mystery Symbols: Mystery symbols appear in every game mode and during free spins. They display numbers and reveal a prize after a certain number of cascades. That number acts as a counter; when it reaches 0, the symbol awards its mystery win.
Super Free Spins: Collecting 2,000 keys awards 5 spins. During free spins, Mystery symbols have no counter and reveal their prize as soon as they land on the reels.
Collecting Keys: Keys sit over regular symbols and award 1-10 when they land in view. Several keys can arrive on the reels together, sometimes producing 50 to 100 keys.
Feature Buy: Players can purchase either ‘full feature free spins’ or ‘top-up’. The ‘full feature’ option adds 2,000 keys immediately, whereas ‘top-up’ raises the existing key total to 2,000.
Mixed-mode Vs Lockdown Mystery Symbols: In mixed mode, the mystery-symbol counters are mixed from 1 to 5 at the start. In lockdown mode, every counter begins at 5, but the prizes revealed are larger.
Bet sizes, RTP and variance
The ‘$’ option sets Min-Max bets of 0.10-25.00. The ‘?’ menu shows the slot’s RTP: 96.46% for lockdown mode and 96.30% for mixed-mode. Using ‘Feature Buy’ gives an RTP of 96.83%. Variance changes according to the selected mode:
- Mixed Mystery Symbols – High Variance
- Lockdown Mystery Symbols – Super High Volatile
Conclusion
The original review points to the 2 game modes, buy feature, mystery symbols, free spins bonus trigger, and cascading reels as a particularly broad feature mix. These mechanics are not all new to video slots, but combining them with Hellcatraz’s retro eighties design gives the game a distinctive character worth exploring.
With 12+ years of experience in the iGaming industry, Evan specializes in reviewing online casinos, analyzing slot games, and evaluating player safety. Their expertise covers casino licensing, RTP, volatility, bonus conditions, and withdrawal policies. Through hands-on testing and independent research, Evan delivers transparent, fact-based reviews to help players better understand gambling platforms, their features, and potential risks.




