At first glance, HTML5 seems to offer some huge advantages for online and mobile game developers. As a purely web-based platform, game makers can create their game in HTML5, and release it on any number of supported devices, from phones to PCs and beyond. But is it really as easy as it sounds?

The platform doesn't have a final specification yet, so its capabilities are very much in flux. It's shown clear signs of promise, and major developers like Zynga have already begun supporting it for their mobile releases, but companies such as on engine provider Unity claim HTML5 "isn't where it should be in terms of performance."

With no clear consensus on where the platform is headed, we've decided to talk to some of the developers most involved with HTML5 to get their perspective, diving into the platform's greatest strengths, it shortcomings, and where it might be headed in the future.

The following is a list of the most important things to know about the current state of HTML5:

1. It's Designed To Work Cross-Platform

HTML5's primary advantage is that it works across a wide range of devices, from PC browsers to mobile phones, tablets, and even Smart TVs. As long as a device uses a browser equipped to run HTML5, it can theoretically serve as a viable platform for HTML5 games.

This offers a huge advantage over native apps, which often have to be completely redesigned for their target operating system. If a developer wants to bring his or her iOS title to Android, for instance, they'll have to make some fundamental changes to their game. With HTML5, that process should be a bit easier.

"We've supported the drive to HTML5 for over a year now, and we see great value in the ability to outfit browser-based games for any device. This is becoming more and more important as gamers play more often and on multiple devices," said Peter Driessen, CEO of major web game publisher Spil Games.

"We think there are a few reasons to go with HTML5," said Zynga Germany's Paul Bakaus, who helps build tech for the company's numerous web and mobile games.

"One benefit is the ability to distribute it easily on mobile web browsers. You don't have to install it, for instance -- that's one significant advantage. There's also the thing with content updating and cross-platform development. If you're building a native app, it's likely that you have to build your app twice on Android and iOS, and on desktop maybe, too. On HTML5, you build your app once, and you can port it to multiple different devices," he said.

In addition to allowing developers to more easily put their games on multiple platforms, HTML5 also allows for easy cross-platform communication, allowing for a host of cloud-based features, ranging from social systems to persistent game worlds.

"What we're ultimately looking to accomplish through HTML5 is true cloud gaming. We support a large online community and it's been obvious that our players, much like gamers everywhere, are increasingly looking to play games on their mobile phones. HTML5 sets the foundation for us to create a seamless experience, which includes social functions, on browsers both on the go and at home," explained Spil's Driessen.

2. HTML5 Offers Unpredictable Performance

While HTML5 might be designed to run on a wide range of devices, there's still no reliable way to maintain performance across varying hardware specifications.

EA creative director Richard Hilleman recently shared his frustrations with the platform at the San Francisco-based New Game Conference, noting that his team's experimental 3D animations ran great on a MacBook Air, but chugged on more powerful hardware.

"On my own computer, which runs on an i7, I couldn't get more than a few frames per second [from our demo]," Hilleman said. He explained that "high performance JavaScript is obtuse at best," so it's hard to predict how an app will run on a given hardware specification.

"I don't know how to explain that to a customer. That's a big, big problem," he added.

Mobile-focused HTML5 developers are particularly susceptible to these problems, as their games need to run on a wide array of smartphones and other mobile devices.

Stewart Putney, an experienced HTML5 developer and former CEO of the recently shuttered Moblyng, told Gamasutra that his company would test its games on literally dozens of devices. "For iOS it is simple: 3GS, 4, 4S, iPad, iPad2. Android is much more fragmented; each handset manufacturer tends to make small -- mostly undocumented -- changes to the browser on their devices. For native Android apps, this is no big deal. For HTML5 apps, it can mean apps simply don't work," he said.

"To get good quality, our apps must be tested on a range of popular devices -- it is the only way to be sure apps are working properly. I believe we will see more testing tools and better standards moving forward -- but Android QA is a real pain point for HTML5 development," he continued.