I keep getting skewered by spikes!

Hint 1 of 4:

You can't walk past them.

Hint 2 of 4:

So you'd need to float over them.

Hint 3 of 4:

Get the broom in the witch houses (close to the back entrance of the castle).
 That's where the kissing fat lady is too.

Hint 4 of 4:

You can get off by using a drop command.