It's easy to ask yourself whether you can make your very own game, but could you do it for real?
I'd say, yes.
I'll give you some 'how-to's about making games, based on 3 Languages you'll need a lot:

• HTML (of course, it's the basic)
• CSS (you don't want your page to be dry, do you?)
• PHP (without this thing, your game interacts NOT)

So, first I'd recommend you to find the images you'll need for your game (including background, content background, sidebar background, splash, and stuff. Maybe even your company logo), make some splash text and save it (can either be in MS Word or Notepad, or such program) then check this page: http://www.subcide.com/articles/creating-a-css-layout-from-scratch/

Trust me, although it says it's out of date, it's VERY useful. Make your own CSS for the home page and stuff, and save it in the folder /css and name it style.css. Then make another CSS file, this time, make a layout for your game (with sidebar, link settings, table settings, and stuff that a game interface would have), and save it in the same folder with the name style-game.css, and if you're finished, you already had one step forward.

Tips: It is HIGHLY recommended to use link colors that match the theme of your game, and the background of your game's content holder (<div id="content">_game_contents_</div>). E.g. the game theme is jungle, the color is dark, then you can use #00FF00 green as the link color.