Learn Spanish (Latin America): El diseño crea mucha expectativa.

In Spanish, expectativa is often used as an uncountable noun when referring to the general feeling of anticipation or hype. Mucha expectativa captures this general buzz. You can say muchas expectativas (plural), but that implies specific, individual goals or demands.

Could I use hace (makes) instead of crea (creates) in this context?

It is much better to stick with crea. In Spanish, words naturally pair up in certain ways. Just as English speakers "build hype" or "raise expectations," Spanish speakers naturally say crear expectativa (to create expectation) or generar expectativa (to generate expectation).

Why is it mucha and not mucho or muy?

Expectativa is a feminine noun, so the word for "a lot of" must match its gender, becoming mucha. You cannot use muy here because muy means "very" and is only used right before adjectives and adverbs (like muy grande), not before nouns.

Since this lesson is about sin embargo (however), how would I use it to add a contrast to this sentence?

You can use sin embargo to introduce a disappointing or surprising result right after this buildup. For example: El diseño crea mucha expectativa. Sin embargo, el producto es malo. (The design creates a lot of expectation. However, the product is bad.) Note that sin embargo is usually placed at the beginning of the contrasting sentence and followed by a comma.