Each planet has 4 or 5 out of the 10 common Meteos, and in varying percentages that they appear (look at the bars at Planet Selection), each planet also has only 1 of the 2 Rare Meteo (Soul, Time).
Each planet has different gravity for how fast Meteo rain down and how fast they blast off with 1. vertical combo, 2. horizontal combo, 3. multiple combos, 4. meteo raining down and having a big or small impact in stoping a mass of blocks shooting up.
Some planets due to the efectiveness of the various types of combos, gravity, and the way Meteo launch have completely different strategies from other planets. For example, Hevendor meteo launch immediately and so you can never launch do massive combos. Vubble's vertical combos are useless (blocks burn out but don't budge) so you have to rely heavily on horizontal combos. Other planets have combos that do nothing on the 1st or 2nd try but blast off on the enxt combo.
That's just a small fraction of differences. The variety between planets is so immense that anyone telling you that the planets are all the same is either lying and/or hasn't played the game.