It's great that there is more competition with Nimble. I'm glad there is more work in this space. After the compiler, package management is the next most interacted-with thing.
Why did you choose "installs the minimal required version" instead of maximum? We currently assume Nimble will grab a higher version, so we don't test the minimum version at all. GitHub tags are a pain. I wish there was a way around them, but I can't think of a quick solution. How do you handle situations when dependencies of the project need different versions of the same package? How do you account for something needing .dlls included as well, especially for Windows? How do you manage something like Pixie which includes 200MB of testing data, which isn't necessary to install? Why did you choose to install into the "_dep" folder instead of, say, just the root project folder? I like that you support URL package names, maybe all packages should just use URLs. Will there be some sort of work with the Atlas checker? At least for the Nim important packages. What Atlas features will you be adding next?