Macbook 13 inch white dust collection

is it common for this model of macbook to collect dust quickly?, because I am having some issues with my macbook, playing a game for a while (maybe 10 minutes) causes the fps to drop the longer I play, if i close the game i can feel the computer become much cooler, once it cools down i can play the game for a while again, but this seems like overheating. i think it may be overheating because of dust buildup (i can actually see bits of dry grass and stuff in the fan, ugh) the computer is used so i have no idea what got in there , so is it worth it to open the laptop and clean the interior? or is it more likely to damage something in the process?.

 

FIXED, cleaned up everything inside, there was literally a shag carpet hanging from the top casing/keyboard when i removed it, the heat sink pipe was coated in dirt! ( what the heck were this computer's previous owners thinking?),
but now everything is fine.

 

upon closer inspection, nothing has changed, the issues are still here