Piercing Blow(http://us.fps-pb.com/) is a 3D lobby based tactical shooter inspired by Counter-Strike. The game features two opposing teams, the Free Rebels (Terrorists) and CT-Force (Counter Terrorists). Piercing Blow was previously known as Project Blackout and is still known as Point Blank in Asia.
Blackshot (http://blackshot.garena.com/) is a post-modern mercenary first person shooter. You are one of the Blackshot, a hired gun who fights for big corporations in their control for resources in a war-torn world. Published for the PC, Blackshot is an action-packed first person shooter that is free to play and accessible to anyone looking for thrilling action.
Gameplay
Piercing Blow has 37+ maps + 7+ game modes (Custom , Death Match, Demolition, Escape, Sabotage, AI Challenge, Search & Destroy!)
Blackshot has 40+ maps and 5+ game modes (Protect the Commander, Team deathmatch, Team Flag Match, Search & Destroy, and Bunker Defense)
Weapon Balance
In Piercing Blow, users can uses matches and earn points to purchase weapons and equipment in the game’s store. So overpowered weapons such as dual-deagles.
BlackShot lacks a balance of weapons. For example : There are GS weapons which require real money and are obviously better than BP weapons that require in-game money. However, it is still possible to win against GS weapons IF you have skill.
Community
The community of players for Piercing Blow seems to be pretty large and active. Lobbies for both the newbie and open channels are usually full during peak hours and there’s enough variety in interest for game types that you won’t have much of a problem find a room for a game type that you’re willing to play.
There is a lot of great stuff packed into Blackshot, it has a variety of games, big community and is fun to play when you are inside a battleground. The variety of games also keeps things interesting and you can see how you stack up against players from all over the world.
Videos and Screenshots:
Piercing Blow ：https://www.youtube.com/watch?v=s0zPDSaNsBY
BlackShot : https://www.youtube.com/watch?v=sEjPYb3VG88
Overall
Well, it's hard for me to say which one is better. You can make the conclusion below the post.