Assassin's Creed Pirates

Mobile Assassin's Creed spin-off, Assassin's Creed Pirates, is one of the best ways to show off what your Android phone can do. As you'd expect from a game developed by Ubisoft, production values are high – there is some expert 3D modeling here, ensuring that boats look realistic even if the naval battles are anything but. 
The cut-scenes, while merely featuring static cartoon characters, also carry charm and there are some lovingly crafted backdrops to do battle in. Even a couple of years later, this is still one of the most beautiful titles on Android.
Free
No ads
No internet connection required
In-app purchases
Requires Android 4.0 or higher

Unkilled 

Unkilled is a linear zombie shooter featuring authentic environments which might be just a little too shiny for the apocalypse. Still, overall high-quality textures and environmental details, as well as plenty smoke and fire, keep it interesting.
Lighting effects are implemented effectively: shafts of sunlight penetrate the underground tunnels you walk within creating a strong sense of atmosphere. There’s also a slowdown effect that occurs when you use one of the game's special items – adrenaline – which really shows off Unkilled's great animations. And you get to pay as Kevin Costner. Or a man who looks suspiciously like Kevin Costner. I think that's a win. 
Free
Ads
Internet connection required
In-app purchases
Requires Android 4.1 or higher

Dead Effect 2

Run of the mill zombie shooter elevated by some flashy graphics: a story as old as time itself. Dead Effect 2 borrows heavily from the likes of Doom 3 and Dead Space, requiring you to navigate through a dark, claustrophobic space station while defending against hordes of mutants.
But it's a particularly attractive mutant-filled space station, and Dead Effect 2 is awash with slick weapon animations in addition to some impressive armor sets and enemy designs. The art is generally pretty strong and it runs smoothly, just don't pay too much attention to the story. Easy enough – it's dreadful. 
Free
No ads
Yes (to save progress)
In-app purchases
Requires Android 4.1 or higher

Epic Citadel

So, this isn't really a game, but if you want to see what your phone or tablet is really capable of, then it doesn't get any better than this. Powered using the Unreal Engine 3, Epic Citadel lets you explore the citadel from Infinity Blade.
There's a cathedral, winding passages, an outdoor bazaar. It's extremely impressive as a showcase of what Android is capable of and great fun to just wander around for a while.
Free
No ads
No internet connection required
No in-app purchases
Requires Android 2.3 or higher

Rayman Adventures

This one isn't going to really test any premium device, but the fact is that it looks sumptuous. It also offers a smooth and genuinely enjoyable platforming experience. In terms of gameplay and graphics, for my money, this is about as close as you can get to the same kind of game on a console.
A real joy to play. The only downside, as it's a free download, are the inevitable in-app purchases that are pushed on you.
Free
No ads
No internet connection required
No in-app purchases
Requires Android 4.1 or higher

Real Racing 3

Real Racing 3 has been criticized for the number of in-app purchases required to progress through it, but the fact remains that it's one of the most graphically impressive games on Android. It's a hefty app – it weighs in at over 1 GB – but it wins our hearts right back with its awesome offline mode.
Free
No ads
No internet connection required
Includes in-app purchases
Requires Android 4.0 or higher

Dead Trigger 2

The second version of the hugely popular HD zombie-slaying game for Android requires high-performance hardware, but when you play it on an HD display, it offers a graphics experience like no other. Even if you aren’t a fan of point and shoot games (or guns in general), it’s worth trying it out just to admire the visuals. When installing, take heed of the game's 465 MB, and be aware of the fact that you can only play when connected to the internet.
Free
No ads
Internet connection required
Includes in-app purchases
Requires Android 4.0 or higher

Wild Blood

This HD fantasy game has graphics that will take your breath away. Wild Blood takes elements from the legend of King Arthur and the Knights of the Round Table and puts them into an action game. Don't hope for too much from the narrative, what matters here is the dazzling imagery. This game, developed using the Unreal Engine, is really one of the best games for showcasing what Android is capable of in terms of visuals.
US$6.99
No ads
Internet connection required
Includes in-app purchases
Requires Android 2.3 or higher

Walking War Robots

It might have a stupid name, but Walking War Robots provides the best blend of graphics and gameplay in the mech genre on Android. It lets you leap into the online arena as a digital war robot, and get on with blowing up adversarial machinery with glee.
Functioning as a 6 vs 6 team game, the goal is to eradicate the other mechs or hold more flags at the close of play. The only real downside is the lack of maps; three maps simply don't provide enough variety for more than a few hours of play.
Free
No ads
Internet connection required
Includes in-app purchases
Requires Android 4.1 or higher

Modern Combat 5: Blackout

Playing FPSs on tablets might never compare to playing them on a PC or console, but Modern Combat 5 comes close. The controls are highly customizable and there are loads of options and modes to explore, including an extensive online multiplayer mode.
The story mode is far from inspiring, especially when compared to some of its immersive console counterparts, but looking at the graphics, there's no way we could miss this one off our list.
Free
Ads
Internet connection required
Includes in-app purchases
Requires Android 4.0 or higher