Name:  Castle of Terror

Developer:  Big Time Gaming

Paylines:  4,096

Reels:  6

Rows:  4

RTP:  96.72%

Variance:  High

Top Payout:  61,720x

Jackpot:  No

Release Date:  October 2022

Features:  Wilds, Free Spins, Progressive Multipliers, Transforming Wilds

About This Slot

Due for release in October, Castle of Terror is the latest release from slots trail-blazers, Big Time Gaming. Unlike much of their output, this is not a Megaways™ game but instead follows the 4,096 paylines structure of slots like Danger! High Voltage and Lil Devil. Still two of this Australian’s finest creations by the way.

The theme is a vampire one, though more in the comic-book horror slot genre of games like Immortal Romance by Microgaming and Bloodsuckers by NetEnt than the more adult-themed games of No Limit City, whose Book of Shadows and Mental are far darker in comparison. That is not to say that you shouldn’t tread carefully here – as day turns to night, those seemingly normal people grow fangs and things get decidedly weirder!

The action takes place against the backdrop of a beautifully rendered country hillside, atop which sits a castle. The sun is shining, there are autumnal colors, a church yard and iron railings in the fore. It can’t stay like that for long – as we shall see, BTG are about to unleash havoc on the reels!

BTG unleash this game at slot sites from October 19th 2022.

RTP, Variance and Top Payout

This is high risk slots gambling at its best. Here are the numbers from the game info sheet:

  • Castle of Terror is a high variance game. When Big Time Gaming do high variance that means seriously high! It will be tough to unlock any big win sequences, but when they come, with all those progressive multipliers, wilds and free spins, the game has the potential to drop some really big wins.
  • Speaking of potential, the advertised top win is 61,720x.
  • The RTP of Castle of Terror is 96.72%, comfortably above average and giving you good value gaming.
  • The default minimum bet for Castle of Terror is 20p.

What does this all tell you? This won’t be a game for the light-hearted, casual gamer. Prepare for some scary slots action!

Symbols and Graphics

Who are these strange characters on the reels in Castle of Terror? Apparently civilised by day, but turning into blood-sucking vampiers at at night. Whatever their intentions, their values aren’t bad at all – premiums peak at 50x which gives you a lot of win power when combined with big multipliers.

Here is the pay structure:

  • Castle of Terror is a 6 reel by 4 row slot with a fixed 4,096 paylines.
  • Wins are triggered by landing identical symbols on adjacent reels – regardless of positions – from left to right.
  • Low payers are the cards from 9 through to Ace with a max payout of 5x for six on a payline.
  • Premiums are the character symbols: the Gardener, the Maid, the Gentleman and the Lady. The Lady pays up to 50x for six on a payline.
  • Wilds play a key role, substituting for all other symbols to form wins. They land as a big W and more appear in the transformative Holy Water feature.
  • Look out as well for Castle of Terror scatters – both silver and gold – which unlock the free spins round.

What We Like

  High top win value
  Enhanced free spins = better multipliers
  Wilds transform to add value to paytable
  Creepy theme works well
  Just above average RTP

What We Don't Like

  Not as feature-packed as Lil Devil
  Tough to unlock free spins

Gameplay and Features

In many ways, despite being without Megaways™, Castle of Terror offers classic BTG gameplay. It is a pulsating mix of wild transformations, progressive multipliers and the climax of a free spins round with enhanced modifiers.

Here is how it works.


  • Holy Water features in both base game and bonus rounds.
  • It triggers at random in the base game, splashing water onto the middle four reels.
  • Two or more premiums are converted into WILDS.
  • Each conversion adds 1x to a multiplier applied to the current spin.
  • The win total is calculated after conversions, after which the multiplier re-sets.


  • Silver Castle and Gold Castle Scatters are needed to trigger free spins. 3 Scatters gets you 12 spins, with 3 more spins for any each additional scatter appearing on the reels.
  • If one of the triggering scatters is gold, then the Enhanced Free Spins round plays out.
  • Holy Water triggers on EVERY spin in free spins rounds.
  • Progressive Multipliers DO NOT re-set between spins.
  • If you hit a 20x multiplier, then 6 more free spins are added.
  • What’s the difference between standard and enhanced free spins? For Enhanced Free Spins the Progressive Multipliers starts at 2x rather than 1x.


  • You can also enter the free spins round via Win Exchange – when you hit a 100x win you can exchange that value for standard free spins.
  • OR … if you win between 25x and 100x play the Gamble Wheel to try for free spins – land on green and enter the bonus round, or land on red and forfeit your winnings!

Our Verdict

Castle of Terror is another top quality, high variance slot from BTG. It ticks all the boxes – volatile maths model, cool theme, big top win, and progressive features that suggest massive payouts are possible on rare occasions when a win sequence unfolds in the rigiht way. Those who enjoy games like Lil Devil or The Final Countdown (both 4,096-win-ways slots too) will get their kicks here.

It’s worth pointing out though that Castle of Terror isn’t quite as intense as Lil Devil – it doesn’t have Sticky Wilds and the multipliers are unlikely to hit the highs of 144x. But, it’s max win of 61,720x is significantly higher than that of Lil Devil (36,403x) which suggests it could deliver on a bigger scale on occasion.

Of course, when reviewing these high risk games we always add the caveat that whilst Castle of Terror may bring drama, it will also frustrate more often. So be ready for some sessions without many wins before you hit pay dirt.