Audio woule be the killer feature, I would make beginner easier or add starter/kid level, now it's still quite complicated:

"¡Hola! ¿Cómo estás? ¿Listo para practicar un poco de español sobre el tema del trabajo? ¿Hay algo en particular que te gustaría aprender o discutir?"

A little bit more guidance in type of conversation would also be great, maybe some tracks, or some maybe some scene to start with (as duolingo does with stories) so you don't have to put mental effort in. (you are in a restaurant order food, the waiter drops drink etc....)