Sure! Here’s the modified text with synonyms and altered sentence structure, while keeping the HTML tags intact:
A horde of undead appeared, devouring everything in sight; you must eradicate them. Press the Z key on the screen to leap, X to fire, or utilize the Up arrow key on the keyboard to jump and the Space bar to shoot.
Use the buttons on the screen or the Up arrow key along with the Space bar on the keyboard to maneuver.
