Great game, performance decaying

Ive been playing Chop Chop for years and had a lot of fun with it. However, overtime, the games performance has seemed to slow down, and it lags a lot more now. I started on an iPhone 3GS, and moved up to a 4S. I dont think they ever updated its configuration to work with the new 4S systems. Anybody else have a problem with lagging?

SoupCan11 about Chop Chop Runner, v1.6