Santhanam shines(literally, as the crew's efforts to make him look like a hero becomes obvious). Coming back to his performance, yes, he shines with his dialogue deliveries and body language. He sure knows how to leave your sides split.
Directors Murugan and Anand, simply referred to as Muruganand have presented the movie neatly without much of a lag in either first or the second half.
Overall View: Santhanam's Inimey Ippadithan aims at making its audience laugh and achieves it convincingly, watch out for the climax sequence.