It would help in the overall temp of the inside of the case if you put more fans in the frot would be good as it will blow onto the hard drive rack and the side panel will be even better since that one will blow fresh air directly onto the motherboard and feed the cpu and gpu fans with cooler outside air.
The stock cpu cooler is only good for average temps and if you get a game that drives up the cpu temps then the stock cooler struggles to dissapate the heat.
This cooler is $29.99 after a $5 rebate and would take care of any heat from the game. You can do the addinf fans first to see what that does and then keep this option in your back pocket in case you have to go with it if the fans don't quite do it.
Usually a game will affect the video card more and with that blowing the hot air out the rear the case should be ok with a side fan giving fresh cool air to the video card.
The bad thing about stock coolers is that they just blow the heated air into the case and a heatsink /fan like the Cooler Master will direct the hot air towards the rear fan.