Different and Welcome!
This game has style, for sure. I never played Shadowfire, but it does remind me of Shadowrun or SpyCraft in its gritty espionage tone. The lizard guy and the robot help, too. The character portraits are nicely evocative of the characters' archetypes. The rest of the game is kind of lacking visually, though. Maybe with a reduction in the size of the character portraits (or just put a glowing border around the currently selected character?), you could have more room for a detailed map, rather than the simple "map screen from Doom" look you have currently. It's not a big minus, but it would be cool to see the same visual style in the map as in everything else. I guess it's meant to be a schematic more than anything, though?
The sound design is simple, but evocative and appropriate. The music is un-intrusive, and while it repeats, it's not annoying. It reminds me of when the DM puts on something ambient to get players in the mood. Good job here. The sound effects could be a little more exciting, but it would get old just hearing "CannedGunShot.wav" for the entirety of combat, so maybe I'm wrong:).
Gameplay reminds me of boardgames, or of taking turns in tabletop RPG's. Individual movement for characters is great, when you want them to split up, but it would also be nice to have a group-move, so that empty hallways don't take forever. I didn't get too deep into the differences between characters abilities, but it might help to more clearly delineate this, unless the differences are just in the bars under the portrait, in which case, I suppose I could have paid better attention.
One more thing. The tutorial is helpful, but might be more so if it included gameplay. I found that once I got into the game, while I remembered some of what was said, I didn't remember everything. Playing through a simple scenario, while tips appear to direct the action, would really help. Tool-tips on buttons and simple labels on the bars and stuff might help here, too. I know your description says there are mouse tips, but I couldn't get them to pop up. Not sure if that's on my end or what.
Over all, great job! I hope we see more from you in the future!