This could have been a Doctor Who episode. And a good one at that, too.
Very entertaining read. Short and easy, thrilling with the right amount of suspense .. and a cliffhanger that made be purchase the second book of the series.
If you like Doctor Who you will love this little book.
And there's the downside of it. It is too close to the the Doc.
You have a trivial name for a time traveller with a lunatic behaviour.
You've got a "weird tech thingy" which he uses all the time.
You've got a time machine.
And there are the bad guys.
As I said, it would have made a great episode and golden thread for an entire season of Doc Who.
However, I'm beginning to read the 2nd book today. Because I love it.