It can be done - what's your Maths like?! If you struggle with Maths (maybe physics), then you will find certain subjects difficult at ATPL; otherwise, you should be fine.
I wouldn't have thought that not having a degree was a factor (but I know nowt about airline recruitment policies); what's more important is whether you can pass the exams.
If the worst comes to the worst, you might have to take some extra lessons if you're falling behind.
Cheers
Whirls