Gargantoonz is an online slot that was developed by Play’n GO and released in December 2023. The game is a continuation of the Reactoonz series, and it follows Dr Toonz, who, after creating a small one-eyed Gargantoon, conducts experiments on it before introducing it to the wider Reactoonz society for riches.
The Gargantoonz slot is set in space, with the one-eyed Gargantoonz set in stasis beside the reels. Symbols in the game include four coloured wild orb icons, and red, pink, green, orange, blue, teal, purple, yellow one-eyed and two-eyed Reactoonz.
Gargantoonz Slot Basics
The Gargantoonz slot uses a 7×7 grid layout with a cluster pays mechanic, where you need to make clusters of five or more identical icons to make wins. You need to bet between £0.10 and £100 per spin, and you can win a maximum of 7,000x your bet, which is fantastic!

The highest-paying symbol in the Gargantoonz slot is the red Reactoonz, which pays £100 for a cluster of five icons, £160 for six symbols, £240 for seven, £400 for eight symbols, £800 for nine icons, £2,000 for 10 to 11 icons, £4,000 for 12 to 14 symbols, £20,000 for 15 to 17 icons, and a maximum of £150,000 for 18 or more icons.
After the above, pink Reactoonz pays £50,000, green pay £40,000, and orange and blue Reactoonz pay £25,000. Meanwhile, teal, purple and red one-eyed Reactoonz pay £4,000 each, and green and yellow ones pay £2,000 each.
Gargantoonz Slot RTP And Volatility
The Gargantoonz slot comes with a return to player (RTP) rate of 96.20%, which is around the average for most video slots. The RTP, if you don’t know, tells you how much of all wagered funds are going to be returned to players over a long time and numerous users. Meanwhile, the game comes with high volatility, so you’re more likely to make large, infrequent wins over regular small ones.
Special Features
The Gargantoonz slot comes with several special features, including four types of wild icons that substitute for all symbols to help you make more wins. There are also tumbling reactions, where all winning symbols are removed from the reels and new symbols replace them. This continues until there are no more wins.
A one-eyed symbol type is chosen to fluctuate on every spin. If fluctuating symbols win, up to two quantum wild icons appear on any spot where a symbol was removed. On non-winning rounds, between four and eight quantum wild icons are added.
If no experiments are ongoing, any winning cluster charges the charger. 20 symbols charge up the charger, and when filled, an experiment is randomly chosen once all winning cascades finish. Another experiment follows if the first is successful and this happens again until all three have been completed. If unsuccessful, the feature ends.
At the start of an experiment, unique wild icons are added to the grid and all existing wild symbols transform into the same chosen wild icon. When an experiment is ongoing, only the wild icons return charge to the experiment charger with their symbol values. 40 symbols charge the charger, while an additional 40 overcharge the charger and increase the Gargantoonz multiplier by one point.
The gamma ray burst experiment adds between seven and nine wild icons to the playing grid. Winning wild icons count the number of symbols in their clusters before removing and counting all instances of the same symbol type. When the symbols are counted, the wild icons leave the grid immediately and charge the charger.
The black hole experiment adds between four and six wild icons to the grid. Winning wild icons count the number of symbols in their clusters before they are removed. Once all cascades have been completed, the wild icons collect all horizontally, vertically, and diagonally adjacent symbols and leave to charge the charger.
The supernova experiment adds between three and five wild icons to the grid. Winning icons count the symbols within their cluster and then remain on the grid, moving one step diagonally on each new cascade if possible. When all winning cascades are complete, the wild icons move eight steps in any direction and collect icons in their path before leaving to charge the charger.
Each successful experiment counts towards the Gargantoon charger and makes the Gargantoon evolve. The gargantoon charger starts with a 1x multiplier and each overcharged experiment increases the multiplier by one point. If all three experiments are successfully completed, the gargantoonz feature is triggered.
The gargantoonz feature plays out in three steps. Up to eight 1×1 wild icons are added to the grid and merge together to form larger icons if they help make more wins. The maximum size is a 3×3 gargantoonz, which is removed from the reel when it makes a win.
Games Similar To Gargantoonz Slot
There are several games similar to the Gargantoonz slot, all of which use a sci-fi theme. One game worth trying is Jeff & Scully by ELK Studios, which uses a 7×7 grid layout with a unique area win mechanic. Symbols here include Jeff and Scully, multipliers, blockers, JFK buttons, pyramids, aliens, cows, aeroplanes, diamonds, and more. For special features, you can enjoy multipliers, re-drops, wild symbols, and more.
Another game worth trying is Mystery Mission – To The Moon by Push Gaming, which uses a 6×4 grid layout with 20 paylines and an RTP of 96.25%. Symbols here include aliens, robots, guns, robotic arms, medals, and planets. For special features, you can enjoy wild scatter icons, mystery symbols, stacked icons, and more.
Gargantoonz Slot Summary
The Gargantoonz slot is another excellent casino game from Play’n GO, and it’s a wonderful new instalment in the Reactoonz franchise. The game benefits from the usual colourful and quirky visuals from the series, and it comes packed with special features to keep you busy and entertained, which is fantastic!
The Gargantoonz slot is best suited for experienced players and high-rollers, as well as anyone who likes the Reactoonz series. If you’re a casual or new slot player, we suggest you find an alternative sci-fi-themed casino game with lower volatility.