I found that after the latest update to TFM makes the mouse very unresponsive. For example, I can't wall jump properly, even when my mouse is sticken to chocolate (?) floor: In the past I can use the "A, W, D" combination to jump, but right now this makes the mouse fall down after the "A" and "W" key press, because the mouse is too unresponsive and too slow to capture the "D" key press.

I tried to switch off those eye-candy features (e.g. not showing particle effects, not showing outfit of other mice, etc.), however none of those helped.

I have been playing this game on Windows 7 and Windows 8.1 for some time, I'm not sure if it is caused by the Flash player update (11.9.900.170).

You're most likely experiencing lag because the devs have decided to make the game play at 60 fps by default, rather than the 36/37 fps (whichever one it was) and also removing the /fps60 command. A lot of people such as myself are having a lot of lag & delays because of this update.

Exactly Primeside, before this new update i never had any lag. once it came out I cant even play deathmatch because of the lag and delays..

I just tried to reload the game and playing in Russia server. I found that if playing in non-full screen mode is slightly better (yes, slightly). I'm not sure if it is related to the root cause...