Nicely Done
The gameplay was good, and I like how objects and the building itself has a durability.
My suggestion would be to add a few more weapons (Though I DID notice the shotgun appeared after a few levels) and a difference between the sword and katana attacks, maybe add combos. The same thing everyone suggests.
My personal suggestions (what I'd like to see, personally) are
-ability to throw agent smiths at each other, or down holes.
-have falling down holes cause damage (if it doesn't already).
-make the antennas into a weapon? They don't seem to do alot but you can still hit them for some reason...
-I've always liked having health bars above myself and my enemies, just to see (more easily) who's about to die.
-Maybe a new weapon every few levels (like I said, I've noticed the shotgun but I didn't see anything else, did I die too soon?) or perhaps a boss at some point?
Overall, very nice game, however.