Hi Lukas,
In general, I like it 
It is clean, simple and accurate.
As for design - it is all grey. But simply adding one-two colors could fix it, I think.
The logo is fine, at least for now.
Some ideas about usability, also.
"Create Project", "Manage Projects" links should not be under Settings menu. Each of them should open separate page, not tabs/panels, like it is now.
Left menu items should be well highlighted, as it's hard for me to understand, what section I am in, even while there's not much functions on the site.
Task management could also be enhanced, but it depends a lot on what you are planning for future.