Devil May Cry 4 Refrain is a port of Devil May Cry 4 to the iPhone. It was released on February 3, 2011, in the United States. At the time of release, Nero was the only playable character,, but after a new update, Dante was added as a playable character. Although the plot for the most part is largely similar to the console version, Capcom has tweaked the story and added some minor differences to the overall plot, a large one being that Nero and Dante's stories have been split into two separate narratives rather than one continuous one.
Reaction to the game has been generally positive. Although it frequently gets criticized for its "muddy" graphics, boring cutscenes, and easy difficulty, reviewers are quick to note that it delivers enough in the action category to make up for it. IGN rated the game at a 7 out of 10, while Slide to Play gave it a 3 out of 4.
The game has all of the same features and storyline as Devil May Cry 4, but the main difference between the two games is that many of the details of the game's locations and overall graphics have been simplified. For example, the ruins of the town in the Ferrum Hills have been reduced to an empty plaza. Character designs have been similarly simplified for the iPhone.
With only 10 levels of a puzzle-maze type, the game is much shorter than Devil May Cry 4. The mechanics of gameplay are generally the same as in Devil May Cry 4, although combos are simpler, and require less button-pressing to complete. In relation with the iPhone, which is a touchscreen gadget, the player needs to utilize a virtual joystick in the lower-left corner of the screen to move Nero and tap at the different icons located in the lower-right portion of the screen in order to execute an action.
For example, a Jump button can be seen on top of the four icons. When tapped, it allows the player to jump, and when double-tapped, it makes a double jump. A Buster key can be found on the left side of the icons which executes the said command. Nero can use the Red Queen, but the combos for it are very simple compared to those in Devil May Cry 4. There is also the Blue Rose icon which acts when tapped, or when held, releases a Charged Shot. There is also an option to combine the ranged and melee attacks into one button, which shows a picture of the Red Queen crossed over the Blue Rose. This serves to further simplify the combat, and will automatically switch between melee and ranged attacks depending on the distance to the target.
Although there is no level up system, a later update added a skill system that allows players to customize their skill sets with a maximum of three skills. Players are granted Red Orbs for defeating enemies, and Proud Souls for clearing missions. The amount of Red Orbs a player receives is only used to calculate his or her score at the end of the level and cannot be used to purchase items, Proud Souls cannot be "spent" but are merely used to award skills based on how many the player has collected.