The park is lovely in the summer and has a good kids playground.
Swimming pool is superb, even if the outdoor bit is a little small.
Shops are run of the mill, pubs are ok - if you avoid The Crown, Lynd Cross et al and don't mind stumping up £3.50 plus for a pint.
I used to work at the bowling alley as a teenager. Not bad - pretty standard really. Avoid the club underneath at all costs.
Two Ryman League football clubs, both playing at YMCA's ground. Quite pricey (about £9 I think) to get in to Horsham and they are struggling at the moment but worth it to experience the team's Lardy Boys support base and fans very welcoming.
A boring place to grow up and fairly small town in attitude, but enough to keep you ticking over for sure.
My Nephew went there for 2 years (I think it was that long) and didn't like it at all. Think he got a scholarship, certainly his parents don't have much money. His sister lasted about a month there before wanting to leave.