Type Defender

One word at a time advances on your base, and the bar above it shows exactly how much time is left before it gets through. Type it correctly before the bar empties and it's destroyed; let the bar run out, or submit the word with a mistake still in it, and it breaks through and costs you a life.

Every five words you clear, the next wave gives you less time per word, so the pressure builds steadily rather than all at once. You start with three lives; lose all of them and the base falls. Your highest score is saved as your personal best.