For me the shop popups were less of a problem, because it pauses the game, but the power popups do get in the way. Maybe try moving the text up and increase the effect around the screen. That way you still get the oomph when getting them but it doesnt cover the table
Also, you probably have something like this, but maybe make more dynamic bosses, or different bosses, just to get a bit more of replayability
Otherwise great game