Echoes has the best boss fights in gaming. Very few games come close to those encounters for me (Shadow of the Colossus is the only one I can think of offhand). Corruption has the worst. That, combined with the 10-15 minute sections, constantly broken up by flying from one world to the next, the interruptive mission directions and repeated guidance stained the whole experience for me. I didn't like the friends that were introduced, didn't like the instant "easy mode" with the PED suit, didn't like that every item upgrade was directly in your path, and I thought the vast majority of all the levels were terribly boring. I remember an ice section being there for like a room or two. Why? Why was that even there?
Ahhh it still frustrates me, just thinking about it. It's a game I feel like I should give a second chance, but I just can't be bothered. I don't like it, especially not the beginning section, and the harder I try to like it the more burnt out I feel by it all. Except for the abandoned ship near the end of the game and the final fight with Ridley, it is a constant stream of disappointments.
Might be worth adding I've seen Trilogy being sold at Super Ks and Targets usually for between $10 and $20. It's perpetually on clearance.