Co-op titles are all the rage nowadays – and in Shiftlings, this is certainly the name of the game. In it, two alien janitors happen across a special drink known as Black Hola Cola, and when one of the extraterrestrials gulps the syrupy substance, his suit inflates like Violet from Willy Wonka. Funnily enough, the characters are tethered together, and so this enables them to shift their new-found weight between each other. Little do they know that they're contestants in a hot and popular game show, which is also named Shiftlings.

This is a quirky 2D puzzle platformer, where you'll assume control of both aliens simultaneously. You'll be able to toggle between them at any time, while another button press will enable to you shift the aforementioned air. Throughout the game's 50 stages (there are five worlds with ten levels in each), you'll have to shepherd the space cleaners safely to each exit. However, this will prove a far from straightforward task, as you'll need to coordinate the two critters very carefully.

When playing solo, this means that you'll have to control both aliens yourself, plotting their movements carefully without getting them killed. With the physics in place, naturally the alien that's filled with air won't be able to jump very high at all, while the deflated Martian will have more range to move. The well designed stages force you to think before you advance; for example, you may need to shift the weight between the alien avatars numerous times in order to reach an out of reach platform, with things getting increasingly complicated as you progress. There'll even be occasions where you'll have to bounce on the inflated extraterrestrial's head in order to get some additional height.

Throughout the game's 50 stages, the critters will come across a barrage of obstacles and traps to avoid. Whether it's getting crushed by platforms, electric barriers, laser beams, or even robots that can slice and pound you, there's genuine danger around every corner. And if that wasn't enough, you'll have to be very cautious of each character's placement, as you don't want to cut off the circulation of the tethered air hose, and send the creatures off to a painful, airless death.

Indeed, one mistake and these creatures will meet their doom; thankfully, there are reasonably placed checkpoints throughout each stage. Your ultimate objective is to activate a switch that opens the exit, and the weight changing duo will need to be together in order to activate these. You'll breeze past some levels in a few minutes or less, while others will take upwards of 10-15 minutes at a time before you happen upon a solution. There are also three collectible Black Hola Colas in each arena, which will really challenge your ability. The only downside is that there's no zoom option, as while you can scroll the camera, it can be hard to see some objects with the naked eye.

Still, this is one of those games that's constantly injecting new ideas. For example, in one world you may utilise anti-gravity beams in order to move around the levels, while another may find you relying on launching each of the aliens through cannons. At the end of every world, there'll also be a "boss" stage. This term is used lightly as you won't actually face a foe in the traditional sense, but rather a massive character in the environment who will attempt to impede your progress. These stages are some of the more fun ones in the game.

Upon completing the worlds, you'll also unlock Time Trials to go back and give yourself a real challenge with. All of the levels are replayable, whether you want to go back for fun, to collect the aforementioned Black Hola Colas, or want to test yourself with the Time Trials. Also, for Trophy hunters, the game does have a Platinum trinket to nab. But despite all of this, the title's best enjoyed in short bursts, as it can grow a teensy bit tedious during long sessions. There's definitely a smartphone-esque feel to the structure, which is apparently where it started life.

Of course, the experience is different in co-op. While it's entertaining alone, switching between the characters constantly can grow tiresome. With a friend, then, you'll control one alien apiece, and thus you'll have to consider when to change weight. This demands communication, which is actually really fun if you've got a good partner. The mishaps are much less frustrating when you've got someone to laugh with – it's genuinely a hoot. Both online and local play options are supported, the only downside being that the online community was practically non-existent as of the time of this review.

Fortunately, it looks nice visually, with a very vibrant and charming look. The game runs smoothly, and boasts fluid animations with very few framerate dips. The game's environments and backdrops are well crafted to boot, and the chirpy settings are accompanied by a fun soundtrack with silly sound effects that helps to flesh out the setting. Even the announcer can be comical at times. Sure, there's nothing especially outstanding in the presentation stakes, but it's more than adequate for what the developer's trying to achieve.

Conclusion

Shiftlings is a fun, quirky title that may surprise those who decide to give it a go. The game's structured like a mobile title, which makes it best suited for short bursts, but you will have fun here – especially if you play with a friend. It's never really ambitious enough to stand out in the crowded puzzle platformer genre, but what you'll find here is a quality pick-up and play experience that will test your wits.