This is great! I like how you made the active word move above the rest; it's an elegant solution to the problem you were having of them stacking up. It's also great having different difficulty levels, and I think the difficulty scaling up the complexity of the words is great. The speed of the monsters is something to tune with more playtesting, and I like your idea of monsters spawning in waves. If you need help improving this project or other future projects, feel free to email me!