I'm not in the casino industry anymore, so I'd like to share a few tips. Enjoy.
Casino games are a unique subset of the game industry. The audience for these games may be older. They want graphics that look and behave like classic games.
The interface must easily allow for purchasing credits
Since casino gaming are constantly monetized, you may want to have a pop-up that encourages you to choose between ($1, $5, $10, $20, $50, $100, or other).
Stick with 2D
The interface should have dimension and depth, but nothing beyond 2D has proven successful. If we're talking class II gaming, 3D has yet to prove it's self. My company had 2 years of waisted development on 3D, and realistic graphics (with nothing to show for it). It confuses the game play and the development expenses skyrocket.
Old School Nostalgia
In updating older games, my company had to be careful not to lose the old-school look of the games (which looked like crap), but the gambling audience is nostalgic about it. I looked to iPhone, Nintendo wii, and Lucky Charms cereal for inspiration.
Things that worked
• 2D Graphics '2D styles prove to work well with extended game play'
• Lower Thirds 'place the GUI along the bottom of screen for easy flow'
• Invest design time in the Progressives 'Numbers turning over sustains excitement'
Things that didn't work
• 3D and realistic graphics 'It takes them out of the zone...it's hard to explain'
• HUD style display 'have to have all controls accessible, lower thirds or side'
• Web Style Layouts 'don't even go there'
Usability sketches would save time. Show the game (slots, win line, poker, blackjack, 21, keno etc) and how it fits with the interface. You'll probably need to plan a login, game selection menu, and pop-up for credits.
There's usually not a budget for a UX designer, Commercial Artist, and Sound Engineer, but that's the talent you'll need just for the design. The coding, that's a nightmare if you're working with poor architecture. Get the features and requirements upfront and try not to reinvent the wheel in this industry.