First of all, I should have played these games MUCH sooner, but not TOO sooner, because younger me would have gotten incredibly frustrated at the non-linearity and lack of direction. (But still, thank god for the hint system)
Anyway... (I'm making bullet points because I can't write a meaningful paragraph for the life of me)
Prime 1:
- Steepest learning curve of them all, due to my inexperience with the series.
- In retrospect the area themes are a bit lackluster.
+ Except for Chozo Ruins, Chozo Ruins is probably the strongest area in the series.
- The scan visor is better in the sequels.
- Magmoor Caverns is annoying to traverse and you have to do it fairly often.
- Phazon Mines is also meh.
+ Really strong atmosphere and music in general.
- Ridley fight dragged out for too long.
Prime 2:
+ Already experienced with the controls and gameplay.
+ The Ing are an awesome threat (and the Space Pirates make a neat cameo)
- Torvus Bog is nothing to write home about (
that subterranean theme tho)
+ Area map design is streamlined.
+ Dark World is spoooky (the load times less so)
+ Sanctuary Fortress is the bee's knees.
- Boost Guardian can go f**k himself.
+ McGuffin hunt feels much more organic (rip Luminoth guardians)
- Emperor Ing fight dragged out for too long.
Prime 3:
+ Hell yeah no forced early downgrade (or at least it felt less like that)
- Door loadtimes are at their worst.
- Motion control gimmics are meh.
+ The most consistently good collection of maps in the series.
+ Elysia is awesome (oh god the shaking, it's freaking me out)
- Helios (the boss) was an absolute chump.
+ G.F.S. Valhalla spooked me quite a bit.
+ Most sensical McGuffin hunt in the series.
- The Energy Cell in Bryyo is the most convoluted mandatory collectable in the series.
+ Least annoying final boss stretch in the series.
- Ending is a bit underwhelming.
All in all, I think Prime 2 is my favourite? Maybe it's because after playing Prime 1, I wanted more of it, and Prime 2 really satisfied that desire, while also remedying to some of my less liked aspects of the first game.
Prime 3 on the other hand feels like a lot like Prime 2, but with motion gimmics (that I do not dislike that much), without some of the bullshit and without the Dark World.
So... Prime 2>Prime 1>Prime 3