During combat:
1) It is often difficult to read the hit point values on the character and baddie tiles when the color of the hit point text closely matches the color under the text. Please put a small, black, background box immediately under the two hit point values. Making the max hit point text pure white would be nice too.
2) In a battle with enemies of different types, when I'm about to use an attack that can target one (or more) of several possible opponents (e.g. magic missile) mousing over each potential target makes an "over-target marker" temporarily appear, displaying the creature type, its health bar, and a lighting indicator. I know how much damage each magic missile does, so I need to calculate how many missiles I need to allocate to each target to have the best effect. The trouble is that I can't tell from the over-target marker what the target's hit points are. To do that calculation I have to hold the mouse stationary over the target, look up at the initiative order list of tiles, discern which one of the enemies is (far too subtly) highlighted, look down to read its current hit points. This is especially inconvenient if all the enemies are "Unknown creature". If the first potential target I try isn't a good choice I have to repeat that process for enemy after enemy. Then, if none of them are one-shot kills, I usually have to go through some or all of them again to work out how to distribute the non-lethal damage. It would be SO MUCH BETTER if the over-target markers displayed the creature's current hit points so all I had to do was look at one place. Maximum hit point would be a lot less useful, but nice to see too, because if I can get one-shot kills on two enemies, I'll likely choose the one who has the highest maximum hit point.
As an additional feature, it would be nice if holding down left-alt displayed the over-target markers for all characters and enemies, to give the player a good way of judging the overall situation.
While I do not disagree - especially that the highlight is too subtle you can target the portraits in the initiative bar directly. This isn't always ideal either as if you do not know which is which you may not have line of sight to the ones you want to target but it can help.
I actually have an opposite suggestion - don't show HP values for unknown creatures. Max HP is one of the things which unlocks in Bestiary for getting familiar with a creature, and with it shown in turn tracker that aspect of Bestiary loses sense. Also, in tabletop you are not supposed to know that a random creature you encountered has 30 or 130 max HP, knowing it right from the start is kinda cheating, as well as knowing that a creature has just 5/130 HP left and not, say, 7/130. You can keep the healthbar or just a "wounded" marker, but please don't show exact values for max and current HP in turn tracker for unknown creatures.
I agree with Дмитрий that "fog of war" would be fun and even sensible with unknown creatures, however I think that'd be non-canon. If implemented, it'd be great to get increasingly accurate Hit Point estimates every time that creature took damage. I'd enjoy the game playing that way.