Recent reviews by Using Tilt Controls

"Fast paced third person action shooter. Fun to do with your freinds. I consider it one of those "It gets better when you get farther in the game" type of games. And might I say having friends helps. NEVER GO ALONE IN THIS. YOU WILL REGRET IT."
September 23, 2013.
4...friggin years ago.
4 years later, with nearly 2250 hours under my belt...and possibly close to $600 out of my bank account...
I can't say it wasn't worth it. Seeing warframe grow up from just a third person shooter where you go out, kill bad guys, make weapons, kill more bad guys and beat challenges...
To this. The Second Dream awakened the Tenno to what they truly are, and to make it even better, The War Within comes in and blows everyone out of the water. We've been introduced to new maps, new worlds, hell, we even got open world coming soon with changes that devs are listening to. A community worth working with.
Pros:
-Free to play: There are no paywalls. The only real paywall is style. Even then, trading can remove that.
-Grind is uphill, but not impossible: RNG might be an ass at times, but it isn't for long enough to give up (Unless we're talking prime parts, they are only for the strong.)
-A dev team that listens to their players: People have actually voiced in their words, and some of them even got accepted. There's even TennoGen, which involves people making cosmetics.
-Actual difficulty curve: You work your way up through the solar system, and they have more challenges waiting for you.

Cons:
-Limited space: You...need to work on getting more space for weapons and warframes, either that or sell what you don't use.
-Some mechanics: Nullifiers. The ultimate asshats out of everything. Corpus levels are evil because of them, don't fret, they can die still. Unless we're talking about some of the bosses then it's gonna be seriously uphill.
-Nitain: The one resource you never hear about only comes around in alerts. Gather it early or else face the consequences of either playing the waiting game or going into the void and testing your levels of insanity.

For what it's worth, if you look at what warframe was, and compared to what it is now, you'd be impressed how it came along in these 4 years. Honestly, I hope to stay with it a bit longer...let's see how far we can carry this hype train.