Wolfram (AKA: Wolfenstein 3D Remake) is a modern HD remade edition of the classic DOS game Wolfenstein 3D, which was developed by John Carmack from id Software in 1992, and treated as the first game work of First Person Shooter (certainly, as early as 1973, the Maze War born in NASA's PDS-1 computer is the only real originator). It was made by Chain Studios from Russia using the Volatile3D II game engine in 2012, released for free.
Kick Ass Commandos is a retro-style, fast-paced shoot 'em up small indie game developed (using Unity) and published by Anarchy Enterprises. The whole game uses the classic pixel style, comes with addictive and stimulating operations, as well as explosive scenes everywhere and driving rhythm. All of these do bring a lot of fun to 2D shooting game fan players.
Rampage Knights is a Roguelike-RPG action game with emphasis on cooperation developed by Rake In Grass game studio. It is mainly inspired from two classic video games Golden Axe and The Binding of Isaac, and fuses the fast-paced design of beat 'em up games and adventure elements in dungeon crawler games.
At first sight of Broforce, I guess most players maybe think of one series of films + one series of video games: First Blood + Metal Slug. AppNee tells you, this is definitely not only a normal 2D pixel game, nothing can stop the crazy enthusiasm from vast majority of players to this game. BTW, IGN gave BroForce 8.8 scores of high praise.
Gibbets is a series of bow & arrow shooting games with unique style and gameplay, developed by Not Doppler. It requires players to have certain strategies and very high operation precision. Also, it's a little bloody!