The countries of Eastern Europe that were "liberated" by the Red Army in 1944 and 1945 were all treated in very similar ways. In all cases, the Red Army treated civilians in very brutal ways. In addition, these countries' governments came to be controlled by the Soviets as they worked to create a sphere of influence that would be theirs after the war.
The Red Army is notorious for its treatment of civilians. Soviet soldiers are known for having raped thousands of women in countries that they "liberated." This happened even in countries such as Yugoslavia where the majority of the population had not been on the side of the Nazis. Even in such relatively friendly countries, the Red Army committed rapes and murders and engaged in looting.
In addition, all of the countries of Eastern Europe had governments imposed on them by the Soviet Union. The Soviets did not want to allow any countries in their immediate vicinity to be possible sources for later invasions of the USSR. Therefore, they set up puppet governments in all of these countries.
What differences there were in the treatments of the various countries might be ascribed to the USSR's attitude towards those countries. For example, some of the worst treatment was dealt out to countries like Lithuania and Germany. These were countries which had provoked the most anger in Germany. Lithuania, for example, was seen as part of the Soviet Union but had been independent from WWI to its occupation by Germany in WWII. The Soviets wanted to stamp out lingering desires for independence and were therefore more brutal in Lithuania than in other countries like Yugoslavia.
The Red Army was brutal everywhere it "liberated." Some countries were treated especially badly, though, depending on the USSR's attitude towards them.
The above answer is right on. In addition, the Soviets, on Stalin's orders, often redrew boundaries of countries and confiscated territory to add to Mother Russia. Poland's borders were shifted west, as was Romania's, Germany's and Finland's. Typically, Stalin would also order the deportation or forced resettlement of tens of thousands of people in the newly acquired territories to fundamentally re-engineer the populations there as to be less likely to revolt in the future.
In the case of Germany, the Red Army was not only brutal (an estimated 45,000 women were raped in Berlin alone), but as a form of reparations for the war was ordered to dismantle German factories, and to pillage the country for iron rails, resources and machinery which was then shipped back to the Soviet Union as spoils of war. One of the reasons why East Germany was so far behind its western counterpart at the time of reunification in 1989 was that it was still recovering from the economic damage of the Russian occupation.
In Poland, the Soviets deliberately held off their forces outside of Warsaw during the uprising by the Home Army resistance forces, allowing the Germans to crush the uprising and kill off the leadership that might be a challenge to the new pro-Soviet regime they planned to install.