Why play a typing game at all
A game is good at one thing a timed test is not: it keeps you practising for longer than you meant to. The pressure of something moving on the screen also stops you looking down at your hands, which is the habit that holds most people at the same speed for years.
What a game cannot do is tell you your typing speed. Scores depend on the game, not on a measured passage, so when you need a figure to put on an application, take a timed test instead. The sensible pattern is a few minutes of a game to warm up, then one clean test at the duration your real test will use.
These games know what you keep getting wrong
Because the games sit on a typing test site, they can read the record of the characters you mistype during tests and lessons, and build their words from those characters. Mistakes made while playing are added to the same record, so playing improves the targeting rather than being separate from your practice. Nothing is sent anywhere: for a guest that record lives in this browser, and for an account it lives with your results.
More games are on the way
This section is new and will grow. Each game is built the same way as the rest of the site: light, free, no account, no download, and no third-party service watching you play.