Which Euripides plays are considered tragicomedies with happy endings?

During the final decade of his career, Euripides wrote several works that are categorized as romantic dramas or tragicomedies with happy endings. These plays are characterized by highly organized structures that lead to a recognition scene, where the discovery of a character's true identity results in a complete and generally positive change in the situation.1

The extant plays identified as belonging to this style include:

• Ion1
• Iphigenia Among the Taurians1
• Helen1

Additionally, the play Alcestis (438 BCE) is noted for being tragic in form but ending happily, having served as a replacement for the satyr play that traditionally followed a set of three tragedies. These works of the tragicomedy type are considered to have anticipated the New Comedy of the 4th century BCE.21