"So how evil is WildTangent? Not very, in our estimation. Its most objectionable feature is that it uses global unique identifier (GUID) tracking when it logs into the game servers. According to WildTangent's privacy statement (www.wildtangent.com/default.asp?pageID=privacy)
, it may collect name, address, phone number, e-mail, and other contact information and, with your consent, may share this information with other parties. It also collects information such as your CPU speed, video card configuration, and DirectX version. The information is used for tuning WildTangent's games and product offerings, and if shared, will only be shared in an aggregated manner, without identification."
All spyware doesn't slow your computer down. It just collects some information from your computer. Nothing that bad to worry about, but being on the safe side of things good thing you uninstalled it.