Glitches in Nintendo Nightmare

Infinite Backups
In Nintendo Nightmare there is multiple ways to get an arbitrary number of backups without cheating by using the cheat box.

First of all the shopkeep in Hyrule Field has a backup for sale. Collecting 999 coins allows you to buy one copy of this backup. While it disappears when you buy it, you can collect another 999 coins and buy yet another backup. This allows you to infinitely farm backups.

Secondly, in one of the Hidden Levels you can find Egadd with a backup in the headquarters. It is the warp pipe just at the entrance of Hyrule Field. Collecting this backup can be done an infinite number of times as the backup is missing the protocols that change it to a collected version of a backup when it has been collected. This allows people to quickly farm a large number of backups.

Bob-omb Wall Climbing
While playing as Mario if you morph into a Bob-omb you then gain a secret power that is the result of an in-game glitch. The Bob-omb has the power to climb walls by continually running towards the walls and repeatedly jumping. If one is fast they will notice that they can jump while not on the ground. This effectively gives players playing as the Bob-omb the ability to arbitrarily climb walls.