There's a new Warhammer 40K game coming this autumn but it's a mobile game subtitled Freeblade.
Nevertheless, this "tap to shoot" game boasts relatively high production values and lets you play as a customisable Imperial Knight, and there are 40 campaign missions and additional dynamically created Patrol Missions. It's a pretty substantial lump of game. You can loot and craft too.
The game is made by Pixel Toys, which was formed by two people in September 2012, and which produced Gunfinger if you've ever heard of that. It will be free to download with in-app purchases for optional armoury upgrades and paint jobs. The team is still apparently working out which generations of phones and tablets will be able to play - I fear for my poor old iPhone 4S.