I have played DK country the last month and finish the game again, also Ive complained about this in another time. The slow down in DK are because of shader generations (you must play all levels for caching but always there is new shaders) and the frame rate sensation can be fixed with VSYNC. The frame limiter maybe is not good in divide each frame time but 59 FPS IS NO FRAME LIMITTER PROBLEM. You must activate VSYNC and play twice time each level and dont cry 