Ttgjyuk

It seems obvious to start by looking at the first few lines on Wikipedia:

Wikipedia on globalisation

Globalization or globalisation is the process of interaction and integration among people, companies, and governments worldwide. As a complex and multifaceted phenomenon, globalization is considered by some as a form of capitalist expansion which entails the integration of local and national economies into a global, unregulated market economy.

Wikipedia on imperialism

Imperialism is policy or ideology of extending a nation's rule over foreign nations, often by military force or by gaining political and economic control of other areas. Imperialism was both normal and common worldwide throughout recorded history, the earliest examples dating from the mid-third millennium BC, diminishing only in the late 20th century.

Based on that, the main difference seems to be that imperialism is something from the past whereas globalisation is from the present. In addition to that, imperialism seems to be more of a one-way street (as in, one party profits and the other loses), whereas globalisation is (at least from the Wikipedia definition) more of a two-way street. Finally, the use of military force seems to be mentioned only in the definition of imperialism, but it's not always mentioned (i.e. the use of the word often).

For example, today's globalisation could be deemed similar because we all live under the economic control of China (because most of our stuff is made there) and the United States has a lot of influence through many of it's companies operating globally (e.g. Americanization)

To what extent are the two different? Is there more to it or are the two rather similar?

The answer is in the quoted passages you've posted. Imperialism is a policy put forth by a nation, whereas globalization is a global phenomenon. Imperialism is unilateral and globalization is multilateral, as you alluded to.

Specifically, globalization is more of a result of a variety of multilateral organizations, treaties, and policies by many governments worldwide. The Bretton Woods Conference was the beginning of the more globalized economy that we have today. The goal was a more stable international system of finance, the globalized economy developed relatively organically over the next several decades.

Additionally, imperialism is historically understood to be a military policy by nature. In the post-WWII era this changed for a variety of reasons. Explicit military control of another country was no longer seen as acceptable as it may have been in the colonial area, and perhaps more importantly the Cold War had begun. Not only could the US and the Soviets not easily impose influence upon a country inside the others sphere of influence without potentially world-ended repercussions, culture was a large factor in the cold war and neither side wanted to be so easily cast as a brute. Though both nations did continue to display imperialistic tendencies towards countries in their respective "backyards" (Soviets in eastern Europe and central Asia, the US in central and southern America). What may be more relevant to this question were the less explicit policies of exerting control over foreign countries that became known as Neocolonialism.

I would posit that there are two types of neocolonialism, intentional and unintentional in respect to the countries that stand to benefit. The growth of the economic influence of a country and thus the spread of its multinational companies and their respective influence is, in essence, an organic process. It is not necessarily always a good one for all involved, but it has in aggregate been beneficial globally. It is the intentional abuse of this influence by a country that can hide imperialism behind the guise of a globalized financial system. This is something the United States did its fair share of at the zenith of the cold war, and something that China is doing today. The general strategy is this: approach a less-developed country and give estimates on the economic viability of [large infrastructure project], knowing that the estimate isn't accurate, have the country take out a loan to pay for the project, the great power builds the project, the economic gains do not materialize at the scale promised, and that country is now in debt to the great power. The global financial framework legitimizes this type of exchange, in which now the great power has undue influence over the less-developed country.

To answer your question concisely: Imperialism and globalization are not the same. Imperialism is an explicit policy by a country of control of another, whereas globalization is the mostly organic result of several decades of growing connections between the economies of the world. However, the financial framework that has come about from globalization has the potential to be abused by economically powerful nations to exert undue influence over less-developed countries.