IMO, they should swap out gemcraft for Cursed Treasure on the popular games list. They're both TD games and have the same rating, but gemcraft has been on the list for a long enough time. I believe Cursed Treasure is a better game, anyway.
Gemcraft is way better gameplay-wise, especially chapter 0.
Cursed Treasure is much shorter and there are less strategy involved. I reached level 36 in two days as I made every level brilliant, that was too easy (hard mode would not really work as the power level is capped very early in Cursed Treasure. Gemcraft have limited resources but unlimited upgrades which made strategies critical such that many people had developed insane ways to play it). Replay value is nearly non-existence.
I wish they'd replace Gemcraft Chapter 0 with the first Gemcraft on the popular games list and replace Cursed Treasure with Age of War, the best game ever.