Effective but limited
Only a few very basic memory games. But I at least found I learnt most of the phrases they did have fairly quickly and was addicted for a bit. However its usefulness is questionable as Esperanto is not a language one would ever ask for the bill or call an ambulance in. Not really worth the high price unless you just want something to amuse you for a few days. "Speech recording and playback" is deceptive. That just means it has sound clips, not that it will listen to your speech.