In infinity mode, it would be GREAT to have the wave number on the block on the left.

I know there's an infinite number of waves, so just having the infinity symbol doesn't help. However, if I know wave 4 is where the second entrance starts, that helps to see. If I know wave 20 is going to have a lot of heavy units, that helps to see as well, rather than having to keep moving the mouse over to check them all again.

Also, you can build traps in the middle of the walls way off in no man's land, which is strange.
It's also annoying that when you have a trap selected, if you click and drag to move the screen, it places the tower. Would be better to be able to click and drag the screen while holding a trap.