1 day in Lavasa: Well-planned city which gives little feel of Cinque Terre in Italy. There you can enjoy adventurous sports, boat ride etc. 1 day in Adlabs Imagica: Amusement park with awesome rides (roller coasters etc) 1-2 days in Matheran: Beautiful hill station. You can enjoy toy train, zip lining and horse ride. You can also do trekking. 1-2 days in Lonavala: Many view points and greenery all around. You can also go for Paragliding in Kamshet. Good Luck!!
Happy Travelling!!