It's sorta both fair and unfair at the same time to compare HAN's style to Tezuka's. On one hand both are going for a similar simple exaggerated look, on the other hand Tezuka is one of the most iconic artists ever as far as cartoony styles go. Still, as >>3707746 pointed out I think Shyna for example has a fantastic design.
I really liked the atmosphere of Omega Factor - it's been a long time since I last played it so I barely remember the story details, but I remember the experience feeling epic, surreal and equal parts melancholic and optimistic. Which is exactly what a lot of Tezuka manga is like.