Correct for everything but the first, not sure why it added "du soir". For the a complete sentence "Um halb drei gehen wir." it's also correct ("On part à 14h30.").
As far as I can tell it's _in_correct in every instance except the first:
À trois heures et demie = À trois heures et demie
Aller à deux heures et demie =\= 14 h 30 du soir [1]
A quatre heures et demie nous partons =\= À 14 h 30 [2]
A trois heures et demie nous allons au cinéma. =\= On va au cinéma à 14h30 [3]
[1] misses the "to go" part and also gets the time of day wrong- which is important because it uses 24-hour clock notation (and so it's obvious that it has no idea what 14h30 means).
[2] completely misses the action ("nous partons") and gets the time wrong ("quatre heures" is "four o'clock", not 14).
[3] Still gets the hour wrong (14h30 to "trois heures", i.e. three).
You'd certainly wouldn't want those translations to "help" you with your appointments in France, or Germany.
I was only referring to the time. "halb drei" is two thirty, which usually means 14:30 unless you specifically say "in the morning". The action in [2] would probably be added if you add a full stop.
and the 4th one is 3:30. I'm also not sure why you introduced "afternoon" into this; it's not said anywhere and it's easier to understand the translation if you just pretend like this is all early in the morning.
Um halb drei gehen -> Aller à deux heures et demie
Um halb drei gehen wir -> A quatre heures et demie nous partons
Um halb drei gehen wir ins Kino. -> A trois heures et demie nous allons au cinéma.