Not a direct sequel, no. You can't really do a direct sequel when time travel is involved, so you basically need an entirely new cast of characters and a completely different plot.
You can't do a sequel if time travel is involved? That doesn't make any sense
Back to the Future 2 & 3
Terminator 2
48 Years of Doctor Who and counting
Bill and Ted's Bogus Journey
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"You know, just once I'd like to meet an alien menace that wasn't immune to bullets." - The Brigadier