Where should I begin with this? Let's get my personal opinion out of the way. I love Zigfrak. It's just plain fun. There. Zigfrak starts you off in the middle of a war torn galaxy, where you are a major factor in the final results.
I have yet to finish the game, but I have played enough to go over the details. First, the game is varying in difficulty from "that was too easy" to "WHY!!!??!?!?!". This can be frustrating at times, but it's overall balanced pretty well.
Being a Unity game, I didn't have any installation issues, so that's a plus. It also runs great on my machine, which I should do a tech post sometime about. There is an outstanding bug for the Linux version however. Cursor Lock. It says it right in the options that this is a bug in Unity that can lead to crashes, jerky controls, etc. The developer has been kind enough to post a link at which you can upvote to get them to fix the issue.
I look forward to what else we'll see from the developer, but that bug is big enough to where I can only give them a toast rating. I know it isn't their fault, but still.
Zigfrak can be purchashed from multiple locations, all of which are listed on their site, where a demo can also be obtained: