Yes you can.
(1) Petronas Twin Tower - mising this place is like missing
Eifferl Tower when one is in Paris. you can do shopping,
visit the Aquaria ( Aquarium ), photo snappings
(2) Kuala Lumpur Tower - go up the observation deck to get
a bird eye's view of Kuala Lumpur, however give it a miss
if there is a big crowd there, don't waste your time there as
only you have to queue to go up
(3) Kuala Lumpur Bird & Butterfly Park
(
http://www.klbirdpark.com )
(4) Merdeka Square - one of the top landmarks in Kuala
Lumpur along with Petronas Twin Tower
(5) Chinatown ( Petaling Street ) - shopping for souveniers
and imitation goods ( haggling is a MUST )
(6) Central Market - souvenier and handicraft shopping
(7) Bukit Bintang - no. 1 nigth life spot in the whole of
Malaysia. Few shopping malls , many pubs and clubs,
restaurants ( asian and western , fine dining )
(4), (5), (6) are all within walking distance
You should be able to visit all the above places in one full day.