What sets Zentris apart are its graphics, or, I'd rather say, the whole style of presentation. It is hard to believe that this game was actually created in the early 90s. The pastel colors, the general understatement, the use of color gradients became the fashion only a decade later.
If you like Sundling's style, you might want to check out Zong, a very beautiful Breakout clone, which in my opinion does more to justify the superlatives the author has chosen to bestow upon it.