I got a job now, which slowed my progression rather hard. Besides, I am also toying with microsoft pivotviewer and silverlight in a different… thread…
Anyway, my game is going quite fine, I handled almost all the problems, tried it on many different computers, and… finally I was able to add my (quite simple and foolish) line-of-sight machanic into game. Now the player only can see in a conical field in front of her ship combined with a small radius circle all around her. It's basically a 2000 x 2000 black sprite with the mentioned field transparent, rotating with the player, and drawn last, so everything else stays behind it. It's quite sloppy but it works for desired effect.
However, there is a rathet strange problem I am encountering. I made the game so that it goes progressively difficult, each spawning of an enemy increasing a global float value by 0.1. This "difficultymodifier" is than used to increse enemy sprites speeds, health, rate of fire etc. But it also increases the players score multiplier. So the game gets more difficult, but the player also gains more points in return. Currently there is no end to the game and the player is trying to achieve the highest score.
The problem I noticed when I decided to see the values on the screen during gameplay, so I could fine-tune them. At some point, the normally 0.1 incrementing float variable increases by 0.09999999999 or something like that, and the difficulty modifer thus becomes sth like 4,399999999999 (and keeps increasing in 0.1 increments) I didnt notice if it did get increased by 0.0999999 again later, but it probably does.
Now normally this is not a big problem for an invisible background worker, but the problem is I tied it to player score. Thus the player socre becomes f*cked up too. Any ideas why this is happening, and what I could do to fix this?