Last time I checked, you could only have one Lambda function attached to bucket events at a time.
Edit: realized my mistake in the wording of my comment above - _how_ I made the infinite loop had escaped me for a moment.
I have a Lambda for processing large files; the first phase is a single Lambda splitting the file into chunks which can be processed within the 60 second limit, and then the second phase is a bunch of the same Lambdas processing those chunks.
(Disclosure: I work with nicksergeant at Localytics.)