It's less than three years since Super Mario Run heralded Mario's smartphone debut. Yet despite much fanfare at launch, largely positive reviews and revenues pushing the $100m mark, Nintendo president Tatsumi Kimishima felt the plumber's performance "did not meet our expectations".
Given the huge affection that gamers have for Nintendo's most-prized IP, Mario's journey from console to smartphone was always likely to ruffle some feathers amongst his most ardent fans.
Next month, Mario returns to mobile with the much anticipated launch of Mario Kart Tour. As one of the best-selling game franchises in history, Nintendo's investors will be hoping that mobile kart racer delivers on the revenue promises that its predecessor could not. While Mario's loyal fanbase will be expecting a player experience on a par with the console version.
With a handful of mobile games now under its belt, what game design and monetisation lessons can Nintendo learn from its existing smartphone portfolio to ensure that Mario Kart Tour crosses the line in winning style?
Back to the free-to-start

To answer this, we need to go back to the start. Or the free-to-start, to be specific, which was the unconventional monetisation mechanic that split player opinion. Asking players to cough-up £10 to unlock the rest of the game after only playing a few free levels, was the nail in the coffin that ultimately led to Super Mario Run becoming a revenue reject for Nintendo.
Next came Fire Emblem Heroes in 2017. Minus the harsh free-to-start paywall mechanic. In fact, none of Nintendo's subsequent mobile releases featured the paywall, despite still referring to the games as free-to-start in the marketing materials. A tacit recognition of the mechanics failure? Maybe.
Despite being Nintendo's most successful mobile release to date, generating nearly $300 Million in revenue in the first year (ten times more than Super Mario Run), Fire Emblem Heroes has issues. Lots of issues.
For a start, the game is clearly not optimised for players in the West, evidenced by the fact that only 28% of game's first year revenues were generated in the US.
It feels like the game is set up for a core audience, meaning that players new to the franchise or genre will find the going tough. Players are left to discover the various screens by themselves and are not properly exposed to key areas of the game. This lack of optimisation must have had a significant impact on the early retention of casual/mid-core players.
The game is bursting with content and features an endless amount of options for players to spend money on. However, its poor on-boarding and overwhelming UI design have limited its potential to be a dominant top-grossing/chart-topping game.