Bugs:1. Mobs stepping on the tp pressure plates and telephoning me before I got to that area.
2. The player starts on creative
3. gamerule keepInventory in false. It needs to be true.
4. Getting the lever is pointless :P
5. The player starts in the first room and not the instructions room. (note: the player will be in the same gamemode, have the same items, and be in the same location you were at when they log in.)
6. The player starts with a stone brick.
7. Touching mobs makes them attack you when you are invisible. The first room will mobs is so small that you are all most forced to touch them.
8. In the first room. Mobs will step over the trip wire usually and spawn an impossible amount of mobs to get by.

Tips for the map:
The design and building was overall really good and I liked the concept. It was super sort though and had almost no challenge. BTW you should have made so a command block gave the player invisibility forever.
In the future, if you make a map like this again, I would like to see more rooms with less mobs. I think it would be cool if the player had sneek by mobs and try to be stealthy. You might want to make it so the player doesn't even have a weapon.

Just my thoughts ;)