That was fantastic!
I have to say you have a bright future in front of you and I expect great things! you have been added to my favorites!
Just two things about the ending sequence, I went back after finishing the first time:
1. the countdown is like minesweeper, after it ends nothing happens, in fact it goes negative, but there is no penalty for not making it out in time. Personally i think the place should actually blow up, or at least white out, and go to the score screen, along with some different text from Mom at the end, i think it would work quite well.
2. there is no difference in blowing up the core or just escaping. I feel that either there should be an alternate ending, in which you are free of Mom, or that the escape shouldn't be allowed until the core is blown up.
Other than preparing your ending for different scenarios the game overall was fantastic and definitely replay-able. The music was delicious and matched the pace of the game well. The style you chose for graphics was perfect and adding dead ends and a variety of enemies made the game challenging and fun.
Also your title could as mean "Kill our Loving Mother". just saying.