Editor’s note: Tadhg Kelly is a games industry consultant, freelance designer and the creator of leading design blog What Games Are. You can follow him on Twitter here.

I’m fascinated by the reviews left by Monument Valley players in the wake of the decision by the game’s developer (ustwo) to price a recent content update at not-free. Ustwo had released the original game at $4 featuring 10 levels. The game was a labor of love and earned many just awards. It also went to sell in excess of 1.4 million copies – a feat that exemplifies how arty mobile gaming can work very well. This latest pack brings 8 new levels to the game and costs a pretty trivial $2. And yet in its wake came a surge of 1-star reviews. But why?

On the face of it it seems petulant to review a game so harshly over such a small amount of money. You can’t buy much for two dollars after all. I suppose you could take yourself off to Dollar Tree and buy two stuffed toys for a buck each and pray they aren’t flammable. You could pop into a Starbucks and buy a Grande Fresh Brewed Coffee, or to McDonalds and acquire a Medium Fries, and have a few cents to spare. But not both.

Or you could throw two bucks into a hit game to buy the fruits of many moons of hard work and obtain hours of further enjoyment. When you say it like that this sounds like a fair deal, no? A trip to go see Interstellar would cost you 5x-10x as much (and wouldn’t be half as much fun) while a fancy dinner out would cost you 30x-100x as much as Monument Valley: Forgotten Shores. More if you wanted to really go nuts. It seems simple, obvious even, that at these kinds of prices games offer fantastic value and that anyone getting such a good deal would be nothing other than overjoyed. But some folks just do not see it that way.

Price in mobile (or indeed any) platform is one of those issues that’s easy to misjudge. I often hear developers paint it as an example of entitlement or overly-expectant customers. As a developer it’s comforting to think that some players are a bit selfish, always on the take and that the task of getting better ARPU is necessarily adversarial. From indies through to casino folks, that mentality leads to thinking about how much can be got from how little. And it tends to lead to confirmation bias because someone somewhere will always behave like a dick.

But when consumers react in groups, such as in Monument Valley’s case, there’s more to it than that. It’s about perception. As developers we make the mistake of thinking that players are automata in systems that sometimes convert them into money. Or we make the mistake of thinking that players are noble aesthetes who want to engage with us on the very highest levels. We over-infer the impact of some decisions and under-infer others. We make the case in our own minds, for example, that putting free-to-play in our games is actually about choice (and then South Park makes fun at our expense). We make the case for price points or charging strategies on what we feel should be true (rather than actually is true).

The thing is it’s not the actual amount that matters. It’s whether you understand what you are selling, or rather what your players think they’re buying. As a game developer or publisher you might see your work as a product, something bought and sold. Therefore it seems fair that you charge in a semi-commoditized fashion. I gave you 10 levels for X, I want to sell you 8 levels for X/2. Good deal!

But players often see their purchase more in the light of a commuter ticket or a pass to a buffet. They judge less on volume of content and more on quality of experience. And having paid for the ticket to go visit your world they feel it’s fair that they can continue to go there. And so they feel aggrieved in situations where extra conditions are then stapled onto that ticket.

I first witnessed this kind of furore in the selling of horse armor as a special item in the Xbox 360 version of Oblivion (2006). In Oblivion’s case the scenario was that the game’s developers sold this extra item as downloadable content for a price over and above the basic game, and fans were up in arms as they are with Monument Valley today. It seemed to violate this sense of having bought an All-You-Can-Eat pass and caused a stink.

Oblivion sold a lot of horse armor. I imagine ustwo will do the same with Monument Valley’s Forgotten Shores levels despite the gripes. Indeed many of their fans followed on from a social media campaign to correct the 1-star reviews with reviews of their own, bringing everything back to an even keel pretty quickly. But does that mean there was no problem at all? No.

The aura of these kinds of events can play through a franchise for many years. Oblivion’s horse armor episode, for example, is regularly featured in “most ignominious things to happen in gaming” lists. It left a dissatisfied air. As mobile gaming in particular looks to expand its remit and become a deeper venue for games as well as just a player and revenue destination, sensitivity to how players think becomes more important. If you do intend to make mobile games and try to capture their “cool” market, be aware of what you’re really selling.