So, I played Warframe.
I am still a low level Initiate so I can't really say if the game has a long lasting appeal but so far, it's good. It's surprisingly smooth and pretty for a F2P game I want to add.
However, for such a well crafted game, their decision to go for that strange organic visual for the Warframes is SO weird.
I admire the artists behind the game for creating a unique look for the game, but it just doesn't appeal to me. I can only imagine how much more popular the game would have been if they stuck with a more mainstream visual like Metal Gear Raiden or Overwarch Genji.