The main problem with circles, in my opinion, is that its hard to see the hp of units that stand in the middle / behind other units. So its also hard to manage units like retreating with low hp units to allow them to recover and so on
I think hp above units is way better for this. Its default in most games for a reason x)
Interesting. I do see what you mean, and I think the cause of that is that the rings are much bigger than the unit, making them overlap. I think the bars are actually much
worse at this because it's harder to tell which bar belongs to which unit, especially if you have a tall unit next to a short unit. With rings, there's no ambiguity about whose health is whose.
I have some ideas for improving this, though. Making the rings smaller and thinner would probably help alleviate the problem, since they wouldn't overlap as much. Also, currently the EP ring is much easier to see than the health ring, despite being much less important. This is because it's larger, it's more vividly colored, and it's outside of the health ring, so less of it is obscured by the units' feet, terrain, etc.
Here's a quick GIMP mockup of how it might be improved for clarity:
You can tell at a glance exactly whose health is whose; smaller ring diameter and thickness leads to very little overlap even in a crowded space; there's more contrast between the EP and health colors without resorting to red and green, which are indistinguishable to a lot of people; the health is featured more prominently than the less-important EP; there's more opacity, which makes it less prone to blending in with terrain and makes the difference between "good to go" and "about to die" bigger.
Maybe there is a way to show selection and health state with circles ??
This confuses me. Don't the rings already show selection and health?
How about having two circles, an outer one for selection/team color and an inner one for EP/health. Or vice versa.
I'm not sure what advantage there is to showing TC in the ring, but if necessary I guess you could just change the color of the ring. There was also a feature added to GAE a while back where you could hold down a key that would show a TC outline of all the units on the screen. It uses the stencil buffer, and
Silnarm said it was really easy to do, so that seems like a viable solution here.