My most played game until Destiny.
It is F2P and very fun... become repetitive fast and has some weird issues with shooting and gameplay in general.
Tons of regular updates.
But take in mind that I did not play it anymore after Destiny... so they could had fixed the gameplay hit collisions... plus for being F2P I had tons of fun.
Edit - I forget to say... the framerate in PS4 was atrocious when have more than 5 enemies on screen... some Void missions you basically played in slowmo

and teleport happened all the time lol