The Rushden Lakes development is due to open in spring 2017, with the 12-screen cinema completed a few months later.
LXB Properties have been granted permission for a bowling alley, climbing structure, cycle hire business and restaurants to replace a planned garden centre.
Local councils had objected, saying it threatened their town centres.
The Rushden Lakes plans have been criticised amid fears the development is could poach shoppers from towns as far away as Kettering, Corby, Northampton and Bedford.
Councils in Kettering and Bedford objected to the cinema and bowling alley.
The amended plans were considered and approved by East Northamptonshire District Council planners on Wednesday night.
A public inquiry in 2013 heard concerns about the development's impact on shops in nearby town centres.
However, council officers recommended that the plans should be approved.
Work on building the main shopping complex, given permission in June 2014 by Communities Secretary Eric Pickles, has already begun.
A cinema and bowling alley are to be added to a £140m shopping and leisure complex in Northamptonshire.