Game is very addicting, but it has a few issues. Some of the upgrades don't quite feel like they're working, and in the case of the radar, it outright isn't. I think it might be a bug in the game that once you upgrade it a second time, the radar doesn't work, even upgrading it a third and final time doesn't help. This is a bit of an issue, and would be worth fixing as soon as can be done. Yes, I have closed and reopened the window. No good. At this point, all I can think of is to delete the progress I've made and try again. Maybe once I've gotten all the way through...