I echo the comments of a couple other posters who were frustrated by the conclusion of the kryptonite cage scene. Yeah, Clark says that he's man AND steel, so you know he's going to survive the explosion. But all of a sudden he's back on the farm and bailing hay? It seemed like there was no finality to that scene, they just moved right on along.
And I'll add another beef I don't believe I've seen mentioned. In the AC/Mera/Oliver scene, Mera gets trapped in the cage, and Oliver just throws a piece of glass into the computer console and the cage bars raise and Mera is free? That felt like a total cop-out. Not too mention the water FX when Mera frees Oliver were sketchy at best.
And, yeah, how did they capture AC? He says they were tracking him (later in the episode), but when we see it Oliver just walks into a room and BAM! there's AC all strung up and stuff? I was like, When did this happen? Dude was just going to search the rigs and now he's captured? Felt forced and rushed.
But on the positive side, I definitely like the introduction of the Anti-Life Equation. I'm guessing that's the "darkness" that is infecting people like Slade. (Reminds me of the Dave Chappelle "Rick James" skit..."Darkness is spreading!") I wonder how it's being transmitted to people, if it's through electronic media or whatever. Definitely very interested in where this is leading.
And when Tess and Lois were talking in the elevator, and neither one knew that the other one knew Clark's secret, you just knew they were gonna find out that each other knew. That's Smallville. Set 'em up, and knock 'em down.