Why low-key hit Legend of Slime is ‘an admon masterclass’


Legend of Slime has earned South Korean publisher LoadComplete over $40m in IAP revenue from around 20m downloads to date, according to both data.ai and Appmagic.

But IAP is just the start. Game design expert Jakub Remiar estimates that in-app purchases are less than 40% of Legend of Slime’s income overall – the other 60% is from ad revenue.

Legend of Slime was released globally in July 2022, and started to gain traction through TikTok in December. It also enjoyed a big download spike in early April.

“Legend of Slime is a masterclass in ad placement integration,” Remiar tells us. “This game probably dishes out around 12-20 impressions per player per day which is 3-4 times more compared to industry benchmarks on ad-driven games.”

Legend of Slime’s ad rewards multiply based on player interaction, making its placements super effective.

Remiar says Legend of Slime has around 30 different ad placements blended into its meta, and it is extra effective because the player gets bigger rewards the more ads they watch.

“The more you buff your character through these temporary 20 minute boosts the stronger they get with each consecutive use,” says Remiar. “The same is applied to gacha draws through ads that get progressively bigger the more you use them. Once you run out of any currency there is a dynamic ad placement that gives you a few more shots on goal.”

Remiar also praised the game’s IAP systems, designed in such a way that “upgrading literally everything makes sense and feels rewarding.”

“You get bonuses from equipping different gear into deck slots that increase your overall power, but this is just the first layer. The second layer of power is given by literally all of the equipment in your whole inventory. Every piece from low rarity to high rarity cumulates into an overall power bonus.”

There’s much more from Jakub and the Two and a Half Gamers crew in their breakdown below:

GameRefinery analyst Jenna Jokela notes that after the game got traction on TikTok in late 2022, it has maintained healthy monetisation rates by regularly adding new features and live ops.

“I have been following this game since last year, and it’s quite impressive on how all the features are interconnected,” says Jokela.

“All of the side modes give resources, currency or passive boosts as rewards that are needed for the main progression, and many of them increase players’ overall power. You can’t deny the power of the simple positive feedback loops.”

Tom Froud, game design consultant at Ludoforma, agrees that progression is slick, with new game modes opening up regularly – though he does have some caveats.

The wealth of systems and upgrades gives players plenty to do, but could confuse and overwhelm some users.

“The myriad of game modes helps keep things feeling fresh,” Froud told us. “At least for the first few days – I have question marks over the long term ability to maintain the content treadmill. The look and feel never really updates or alters to a point where it is visually more varied.”

“A nice subtle USP is how it marries that constant sense of progression with clearly marked ‘stages’ of progress, where you take on a boss before moving to the next stage. So whilst you’re always getting more powerful there is also a clear new short-term goal ahead of you at every step.”

“The interaction alone is satisfying even if the amount of stuff you are exposed to is bewildering,” he continues. “The onboarding is quite mad – you are shown a lot of stuff and that would definitely be off-putting for players new to the genre.”

Legend of Slime’s ad integration is some of the best our experts have seen.

“This may well be fine for their target audience but it will cause more casual players or those new to the genre to churn. But I think the people who do stick around and spend certainly have lots to spend on.”

Froud agrees with Remiar that the game integrates incentivised ads really well – “It’s an excellent idle game and an even better ad machine,” he adds.

“There are lots of opportunities to watch ads, but they always feel worth watching. It’s natural to think this will lead to ad fatigue but I think the idle game play style makes this less likely. However I’d say the myriad of upgrades and goals is quite bewildering.”

“Idle games and ads are a match made in ad monetisation heaven and this is the best coupling I’ve seen. It just needs some social features to drive engagement further.”

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