GunFu Deadlands is a super hard retro styled indie game. You play a wild west guy, and have to kill all the bad guys on each of 10 levels.
This is a stealth game, so running out guns blazing will not work, instead you should move with care, and take out your targets one by one. You aim with the mouse, move with the keyboard, and can activate a 'bullet time' feature, which slows everything down giving you a light advantage.
Visually, GunFu Deadlands is extremely basic, but the gameplay makes up for it. When you get killed, you start the level again, and dying is pretty common as the enemies are sharp shooters. Noise attracts them, so thinking strategically is very important - for such a simple looking game, it's surprisingly deep, and the blocky killers are much smarter than they look!
If you're tired of games that hold your hand all the way to the finish line, GunFu will certainly challenge you. One shot death, and quick drawing enemies make this something that requires practice and patience!
GunFu Deadlands may look basic, but it's a really enjoyable and challenging little shoot 'em up.