Yes or no on NS2
I bought NS2 for thr ~6.50$ USD saleprice earlier this year.
Worth the sale price not the fullprice. It's an Aliens vs Marines FPS/RTT hybrid where both teams have an RTT commander that directs construction/expansion/research/grandstrategy/minorsupport while all their units are actual players in an FPS. VERY different playstyles and strategies for both sides.
Was originally a HL1 mod, now is a source mod with it's own executable. Compared to the original, NS2 is
HORRIBLY unoptimized.
DO NOT GET IT IF YOU DONT EXCEED THE RECOMMENDED SPECS. I'm not joking. I exceed the recommended specs and it still turns from a full 60 FPS into a slideshow on the minimum settings at the worst possible times.
I've logged over 30 hours, and it IS broken, but still very enjoyable. Play green (literally green) servers which are the noob friendly ones at first. The game HEAVILY favors the Alien team, and I'm not just saying that as a butthurt Marine player. The NS2 stat tracker shows all public matches for every patch/version of the game has over 50% wins for the Aliens, and all competitive matches Aliens consistently win 2/3 games at a minimum. From experience I can tell you it's largely because the skill ceiling on the Aliens is insane (Equally skilled Alien and Marine player, the Alien can do more damage), and going from 60 to 2 FPS because of shit optimization hurts the Marines (guns against tiny fast targets point blank) more than the Aliens (melee). All experienced players tend to play Aliens because they can do more solo, and all new players tend to drift towards Marines because it's more familiar, which really doesn't help the imbalance.
If you play nothing but quick pub games it's nearly a 50/50 (~55% Alien victories) balance, and actually very fun. As much as I bitch about the game balance, the two teams are so different it's amazing they managed ~55/45% for public matches. You'll still run into the one or two veteran Alien players that can kill 6+ Marines in seconds at the start of the game, but after that a team scramble vote usually passes.
I think you can get more than 6.50$ of entertainment out of it. Just stick with your team whatever side you're on and you'll be better than the average new player.