In recent years, French games publisher DotEmu has established a reputation as one of the best sources of classic games updated for your smartphone. Its work has meant that players have been able to enjoy classics such as Double Dragon, Another World, and R-Type, while on the move. It was also instrumental in the PS4 release of Final Fantasy VII last year.

Its latest release, the action role-playing game Titan Quest, has been its most ambitious yet. The much-loved 2006 PC action RPG was rebuilt from the ground up, substituting touchscreen controls for keyboard and mouse.

Gamasutra talked to DotEmu's CEO, Cyrille Imbert, to find out more about their general process, and how it played out with their port of Titan Quest.

RESEARCH, RESEARCH, RESEARCH

The start of their process is simple enough. The team spend a lot of time playing the original game so that they get an idea of the look, atmosphere, and general feel of the title. Alongside that, Imbert explained that research is conducted on what the original creators produced alongside the game, so that they can understand the thought process behind what was being created. "Sometimes, the original source codes have been damaged, are incomplete or simply lost," explained Imbert. "To cope with that, we use technologies such as emulation (SNK titles), reverse engineering (Final Fantasies) or a bit of everything."

Considerations are made for various technical aspects of each game, such as the amount of memory used, the frame rate, and the screen ratios involved. Given that many of DotEmu's titles work on both iOS and Android, they have to adapt to different screen sizes, maintaining the appropriate look. "It's very challenging, but this is what makes it so interesting to work on," noted Imbert.

ADAPTING THE INTERFACE

Taking one interface, such as a mouse and keyboard based control system, and transferring it to touch is a particular challenge. The DotEmu team starts by benchmarking. They look at similar games on the same platform, and deduce what works best. A list is then drawn up of actions that the game will require players to do, before efforts are made to prioritize certain actions. "By combining both considerations, we create a rough interface, keeping the best from existing ideas and creating new mechanics to fill the holes caused by the original being on a different format," explained Imbert.

Once that's been determined, work on the look of the menus and interface is conducted, ensuring that it'll still look as good on a small screen as it once did on a bigger platform. DotEmu tries to avoid virtual buttons wherever possible, although sometimes they are required.

"We don't want to alter the gameplay," he explained. "[but] sometimes, the only solution is to have a D-pad and buttons." He cites YS Chronicles 1 & 2 as examples of this need for virtual buttons.

Games as varied as Pang Adventures, Another World, and The Last Express have all garnered very positive reviews. DotEmu's latest title, Titan Quest, has had slightly more mixed feedback, but it's also been the company's most challenging port yet.

THE CHALLENGES OF OPTIMIZATION

The hack n slash style RPG, is not only fast paced, and developed with a keyboard and mouse in mind, but it's also about 60 hours long. Multiplayer and content from expansion packs fell by the wayside.

Optimization was vital here, even with mobile devices being increasingly powerful."It took us about 6 months before we started to run the game on the latest iPhone at a decent framerate," explained Imbert. "It's only with the latest devices that you will be able to have a nice 60 FPS with Titan Quest." That's also why there Dot Emu is still working on an Android version. (It's due on July 7th.)

DotEmu may have bitten off more than it could chew when it comes to the current state of iOS hardware. Still, the Titan Quest port is generally considered to be one of the best hack n slash RPGs out there on mobile devices. Some iOS reviewers grumble about the frame rate heavy battery usage, and a recent patch has provided users with a ‘low graphics’ option to help more people enjoy it.

Still, the company would rather alienate some potential players than simplify the graphics too much more. As Imbert stressed, “our mission at DotEmu is to keep the look and feel of the games we work on, whatever the platform."