Over the weekend a little game called Mr. Jump crawled to the top of the iOS App Store. By crawled, I mean jumped…a super, mega, Hulk-strength jump right into the #1 game spot. It’s clear that lots of people are playing, and enjoying, Mr. Jump. But why?

At first glance Mr. Jump is a late-to-the-party Flappy Bird clone with a platformized landscape. Players tap the screen to get Mr. Jump to hop into the air to varying heights based on how long you hold the tap. Obstacles include pits, spikes, and low ceilings. Hit any of those, and it’s game over.

While first glance may present obvious comparisons to Flappy Bird, the main difference between the two games is subtle, but important.

Where Flappy Bird was randomized every time you play, Mr. Jump is not. The levels (of which there are currently 12) are all intricately designed and never change. A spike trap will always be in the same spot, in the same level, each time you play. This allows players to slowly progress through repeated attempts. Frustration arises only from the player’s own lack of ability, rather than the game taking a surprising or unfair turn.

That mentality shift was enough to keep me trying Mr. Jump long after I would have given up playing Flappy Bird. I have the feeling the same is true for the vast number of Mr. Jump’s (already!) five million users.

How far can you jump in Mr. Jump? Find out by downloading the game for free in the iOS App Store.