This is one of the best flash games I have played, and I play a lot of them. The turn based combat system is reminiscent of Fallout 1&2, which is refreshing. It adds strategy. As far as some negatives go, zombie no-clip is a little detracting, and makes things too easy. You can sit in one spot and they will walk through the walls to get to you, instead of forcing the player to go into an enclosed area. The only other negative comment I have is that the game was too easy. However, I can't remember if there was a difficulty setting to choose from. More good points are the open ended maps, the hidden areas and hard to find search spots. I spent a couple hours on this just because I wanted to find everything, and I think I did, I was pretty thorough. That actually brings me to another negative, the weapons. In my opinion there isn't a big enough variety of weapons. I don't know if the item generation is on a randomized system which means I couldn't possibly have picked up everything that was possible, and I hope that is the case.
In a nutshell:
Harder (if there isn't already a difficulty setting)
Add more bosses
Fix the zombie no-clipping
More variety of skills, what are currently there are nice, but I would like to see more that apply to melee, or add to overall accuracy, etc.
What to keep:
Open ended maps
Current combat system (I really like Fallout 1&2 if you can't tell =D)