Continuity mistake: When Lacy is in outer space grabbed by Nuclear Man, she slides down dramatically and grabs on his wrist. Half a second later, the sliding effect is gone and she is now floating relaxed, grabbing the upper part of his arm.
Continuity mistake: When Nuclear Man arrives on Earth, he enters a shady place which makes him lose his power and cools his body, producing some frozen-like smoke. The next two times that he enters a dark place (inside the elevator and in space) he doesn't produce the smoke.
Continuity mistake: Lex's fat assistant enters the place with the missiles' control panels. Outside he is seen entering through an open door. From the inside, the door is closed and he enters a second later.