Civ IV had some nice tooltips. I could tell the size of the enemy army by mousing over them.
1. In Civ V, you can mouse over another unit and see it's Strength, but you'll be unable to tell what it's HP is. Annoying.
2. The Strategic Map forces you to look at the units, improvements, and resources. In Civ4 you could pick and choose which effects you wanted to see; not just some. Annoying.
3. In Civ4 when moving a worker, you could know by holding down the right-click mouse button what you could build in the tile. That feature is noticeably absent here.
4. Civ4 had a ton of custom game options. I see hardly any such options here.
5. Civ4 had Combat 1. Now we have Shock and Drill. Now I have to pay attention to what little tile my opponent is under to figure out what promotion I want to get; not fun.
6. In Civ4 I knew the combat Percentages with another unit before starting a war. Now, I have to declare a war and then I can find out if the combat odds were such that starting a war was justified.
A lot of little things that show attention to playability are absent.