They really need to update the way Piranha Plants in pipes are set up. The way it is currently, they get out of the pipe for the first time when you're about to go on, under or next to it. They should be out when they appear, so you understand right away the pipe has some hazard in it.
As it is now, you basically have to pause in front of every pipe to be sure you won't get killed. When you design levels, that obliges you to be careful that the player understands this is a hazard area (making them pause to grab coins for example).
Also, what's with bugs when stuff appears? I created a zone with four winged Koopas, and when I play the level, sometimes I see four, sometimes I see two, and most times I see only three. I also had Piranha Plants get stuck in trampolines when I designed them to be two blocks above! I hope this gets fixed.
