There's a lot of good to this game, and I'll do it in a pro/con format:

Pros:
*You don't need to buy in game money. You can trade parts for it, and get what you want. Granted, Prime Access does require money. It also gives quuuuuuuite a bit.
*Every weapon is obtainable through crafting.
*You can play by yourself, with friends, or if you're feeling really dangerous, ONE friend.
*DE support is very helpful, and very responsive. The game is veeeeery community driven, and the players have changed the tide of the game.

Cons:
*The game can become FarmQuest 2077, as every weapon and Warframe does take some amount of rare resource. It is doable, though.
*Updates can be slow, and usually veteran players run out of content to do very quickly, causing players like me to take long breaks.
*Kickbot won't sing if you private message them.

All in all, I do recommend this progidal Free 2 Play game.