Game slows way down during the fight phase and becomes unplayable

[Eat__Food]

I just started playing Sanctum 2 again and was enjoying it until it started to slow down so much during the enemy waves that it is unplayable.

I'm on a MacBook Pro with Retina Display. Running OSX Yosemite 10.10.1 with all of the specs that go with a 2013 edition. The graphics are Intel Iris 1536 MB.

Any help on the matter would be greatly appreciated.

[Sapperdoom4]

i have this issue with my macbook pro as well. but it gets worse than just slowdown, sometimes the enemy A.I. stops working entirely due to the increased slowdown/lag(even worse when they freeze out of bounds and i have to resart the map), and only once have i crashed due to this. all my settings are on low and i have done every to speed my computer up yet im not getting any success. any help would be apperciated.