Secrets of Atlantis

Secrets of Atlantis is a NetEnt online slot from 2016, and we've been running it in free-play demo mode to see how it holds up a decade on. The theme is the lost underwater city: sunken columns, glowing ruins, that whole Atlantis myth. NetEnt built its name on licensed slots and polished originals, and this one sits firmly in the latter camp. It's a five-reel game with a published RTP of 97.07%, which is high for a slot of this age. Medium volatility, and a top prize of 1,600x your stake. You can try it without signing up or spending anything, which is the version we're reviewing here. This Secrets of Atlantis slot review covers how it plays, what the numbers mean, and who should bother.

Secrets of Atlantis theme, look and mechanics

The look is classic NetEnt. Deep blues, gold trim, and symbols that lean on the Atlantis story rather than generic fruit or card suits. It reads as a mid-2010s release, and that's not a knock. The studio's art held up better than most of its contemporaries.

Mechanically, this is a five-reel slot with 40 paylines. Our sources confirm the payline count, so we can state it. The standout feature is the colossal symbol. A single symbol can land across a 3x3 block, covering nine positions at once. That's the hook, and it's why the game feels different from a standard 40-line slot. Colossal symbols create bigger cluster wins than you'd normally see, and they're the reason the base game stays interesting.

There's also a nudge wild. When a wild lands, it can nudge to fill more of a reel, which lifts your chances of connecting a line. Some sources mention stacked reels and wild reels in the base game too. We couldn't verify every detail across all sources, so treat the wild behaviour as the headline and the rest as supporting.

The game pays both ways on some configurations, according to the ranking pages, though we'd rather flag that as unconfirmed than state it as fact. What we can say: the base game carries real weight here. You're not just spinning to reach a bonus.

RTP, volatility and what to expect

The published RTP is 97.07%. That's the number to remember, and it's genuinely high. Most modern slots sit between 94% and 96%, so this one returns more to players over time. It doesn't mean you'll win more in a session. It means the house edge is smaller across millions of spins.

Volatility is medium. You'll get a mix of small and mid-sized wins rather than long dry spells followed by one huge hit. The max win is 1,600x your stake, which is modest by 2026 standards. Some slots now advertise 10,000x or more. This one doesn't, and that's fine. It's built for steady play, not lottery-ticket swings.

If you want the full picture on how these figures work, our guide to slot RTP and volatility explained breaks it down properly. The short version: high RTP plus medium volatility suits players who want longer sessions with fewer brutal droughts.

One thing worth noting for UK readers. We can't confirm the licence details for this specific game from our sources, so we won't guess. If you're playing for real money, check the operator's licence on the site itself. Look for UKGC authorisation, GBP deposits and withdrawals, and GamStop registration. Those matter more than any single slot's RTP.

Playing the Secrets of Atlantis free demo

The demo runs in your browser with no signup and no deposit. You get virtual credits, the full game, and every feature unlocked. Nothing you do affects your bank balance.

Give it 10 to 15 minutes. That's enough for roughly 100 to 150 spins at a normal pace, which is plenty to judge the feel. Don't write it off after 20 or 30 spins. Colossal symbols and nudge wilds don't show their value immediately. The base game needs time to breathe.

A few honest pointers from our testing:

• Watch for the colossal symbol landing. That's when the game wakes up.
• The nudge wild is your best friend in the base game. Track how often it triggers.
• Medium volatility means patience pays. Don't chase losses in demo either. Build the habit now.
• Compare it against other free casino games before you commit real money anywhere.

If you're new to judging slots, our how we rate games and casinos page explains what we look for. It's the same lens we used here.

Should you play Secrets of Atlantis?

Yes, if you want a high-RTP slot with medium volatility and a mechanic that rewards patience. The 97.07% return is the real draw. The colossal symbol gives the base game a reason to exist beyond spinning for a bonus. And it's free to try, so there's no downside to a 15-minute test.

Skip it if you need huge max wins. At 1,600x, this won't satisfy jackpot chasers. Skip it too if you want a modern bonus-buy game with escalating multipliers. This is a 2016 slot, and it plays like one.

For everyone else, it's a solid pick. NetEnt knew what it was doing. The theme holds up, the maths are generous, and the demo lets you decide without risk. When you're ready for real money, compare best online casinos and check the licence before you deposit. And keep responsible gambling tools close at hand. Set limits, use GamStop if you need it, and treat slots as entertainment, not income.

18+ only. Play responsibly. Demo play uses no real money.