Dead Cells is a great game. You can read all about it in all the reviews that came out for back when it originally released in August of 2018. This mobile version is the exact same game, but ported down to work on iOS devices. This is what this review will focus on, with the ultimate take-away being that this version of Dead Cells is competent and enjoyable as long as you play it with a controller.
Dead Cells's action roguelite gameplay is fast and satisfying, provided you have an adequate means to control your character. Using touch, I found controlling most aspects of the game to be quite difficult. This is partially due to the very nature of touch controls, but the game also makes matters worse with its button layout and iconography. It's hard to tell what buttons do what, and it's nigh impossible to activate more than one ability at a time.
There are a few different ways you can adjust the touch controls in Dead Cells, but none of them get anywhere close to capturing the tight feel of playing the game with a a controller. Fortunately, this version of Dead Cells has perfect MFi controller support though, so if you have the requisite hardware, you're in luck.
Another wrinkle in the iOS port of Dead Cells comes in its presentation. No matter whether you're playing on an iPhone or an iPad, the game presents the action using the entire screen (aka no widescreen bars). While this sounds great, it also ends up making the game feel a little different depending on your device's aspect ratio.
When playing on an iPad, the additional vertical screen space makes jumps feel shorter than they do playing on a wider screen. The game isn't actually shortening your jumps, but the visual trickery at play here can make it tough to adjust if you play Dead Cells between multiple devices.
Designed for other devices
If you plan to play Dead Cells on a single iOS device with a controller, you should have more or less the same experience as someone playing the game on console or PC. The only remaining difference is that you'll be playing on a mobile device. Depending on your habits or expectations with mobile games, this could also affect your enjoyment of it.
A core tenet of Dead Cells is repetition. You fight your way as far as possible, try to unlock a few things before you die, and start all over again. Many of the unlocks in Dead Cells have a clear roadmap as to how to unlock them, though there are some special unlocks that are a bit obtuse. In fact, there are doors, items, and map sections are inaccessible for large chunks of the game, with no clear way to gain access to them. This while this might be all well and good for an experience you'll be luxuriating in front of from the comfort of your couch or chair, it can test your patience while playing in bursts on the go.
The bottom line
Again, there are plenty of great pieces to read on the ins and outs of what makes Dead Cells a great game. This mobile version is that exact game, but it's a little harder to enjoy on this particular platform. So, unless the iOS version of the game is the only way you can play Dead Cells or you want to have yet another way to play it, I'm not sure why you'd get this version over the ones that came out last year.