Let's see....Spider Ball would obviously go along Spider Ball tracks in the Prime Trilogy. Speed Boost will obviously come into play when you need extra speed in most of the 2D Metroids. Boost Ball obviously is meant to be used on Boost Ball Half-pipes (OMG). Speed Boost obviously destroyes those "arrow" encrusted blocks in Super Metroid considering how the symbol on the block looks exactly like the upgrade when you obtain it. Gravity Suit clearly goes with water in Metroid Prime. Varia Suit obviously protects you from the heat.
Dark Suit would deal with Dark Aether protection (since it's an upgrade) same goes for the Light Suit. Hazard Sheild would obviously protect you from the Acid Rain on the Pirate Homeworld. Grapple Beam use is also obvious, in both Super Metroid and in the Prime Trilogy. Power Grip obviously has something to do with how you grab things (and you quickly see that it's ledges). The Hi-Jump, Space Jump, and Spring Ball all have to do with getting to a higher place in the respective form. PED Suit and whatever upgrades that come with it obviously will deal with Phazon. Same with the Phazon Suit. It's really not that difficult to figure out the uses to these upgrades....so....
The Boost Ball half-pipes weren't even revealed to be boost-ball half-pipes until you got the freaking Boost Ball, where the game goes "OH, YEAH, THOSE HAF-PIPES R 4 THIS!!!!11!" and points out the important ones for you.
Speed Booster blocks were NEVER obviously Speed Booster blocks - they looked exactly like normal wall tiles of that environment. The only way I could figure out that they were Speed Boost tiles were using the obvious method of running through it or revealing it via Power Bomb (Fusion and Zero Mission) or X-Ray Scope (Super Metroid) for the tricker sections, such as the destroyed Mother Brain chamber in Zero Mission. The only time Speed Booster blocks looked like, well, Speed Booster Blocks, was after you revealed them.
Gravity Suit only "clearly" goes through water in Prime AFTER you got the bloody suit. When you're in a watery area that you need the Gravity Suit for, there aren't any sections or neon flashing signs saying "YOU NEED THE EFFING GRAVITY SUIT/GRAVITY THINGAMAJIG IN PRIME 2 HERE". Hell, for people like me, who STARTED with Prime 1, it wasn't obvious at all that I had to go the Gravity Suit to get through the crashed Frigate.
And how the hell would the Varia Suit "obviously" protect you from the heat? The only people who would know that would be series veterans. There is no indication whatsoever, not even when you come across a hot or cold environment, that you needed the specific Varia Suit item to get through. It's the same thing as the Gravity Suit - no neon signs.
Hazard Shield would "obviously" be used for the Acid Rain because it's called the HAZARD SHIELD. Key word: HAZARD. xD;;
Grapple Beam in Super Metroid wasn't really obvious - when I first played the game, I was always wondering what the hell those blocks were...until I finally learned the hard way that they were for the Grapple Beam, five minutes after getting it. Again, no neon signs saying "USE THE BLOODY GRAPPLE BEAM HERE, YOU MORON". The obviousness in the Prime games was born out of necessity because of the system: you locked on to Grapple Points, thus they MUST be obvious or else players are going to get frustrated spending ten minutes attempting to lock onto what appears to be a grapple point. This is not the case with Hunters with the brightly-colored force fields.
Power Grip was only an item in Zero Mission, which, BTW, did NOT have brightly-glowing ledges to grab onto like in Prime 3.
Anyone with at least one brain cell can figure out that increased jumping capabilities = higher places. Far different from the force fields in Hunters.
The problem people have with the Hunters upgrades is that it is BLATANTLY obvious where to use them, even without scanning (which allowed you to easily figure out what weapon to use on that thing over there), and the fact that they're FORCE FIELDS. No specially colored rock or anything, no special statue powered by one weapon, no weapon-specific obstacles, NOTHING. Just force fields with those effing annoying things on it. Its obviousness isn't because of common sense (Hi-Jump, etc.) or because you figured it out (Gravity Suit), it's because of sheer laziness.
*cough* Anyways, I myself kinda enjoyed the Hunters single-player, though I thought that there was a lot of lost potential, especially with the bosses and the encounters with the other hunters and plot. Man, I thought Prime 2's plot was bad, Hunters was even worse - GO GET THESE EIGHT THINGS AFTER FIGHTING THESE SAME BOSSES OVER AND OVER AGAIN KTHXBAI. I liked the new weapons (except for the BattleHammer. Gravity, boo!) and the precision the controls allowed, however hand-cramp inducing they were, and I liked the other bounty hunters, Trace and Spire especially.
What I liked most about Hunters was the multiplayer. I was fond of normal battling against random people, "outsniping the snipers" as any character (and I could headshot kill people while being flung in the air!!!), and just overall having fun. What ruined it, however, was the freaking cheaters. I stopped playing multiplayer after I encountered a death-alting Sylux who wasn't in his Alt form - I didn't want to lose more rank points to assholes who would cheat.
Things I didn't like about Hunters: the repetition (and why aren't the places blown up after the escape sequences!!!!) with the bosses, plot, and levels, the one-hit-deaths, the hand-crampingness, and the cheaters. I also, for the first time ever in a Metroid game, didn't like the music. Music is a very important thing to me, especially in the Metroid series, which contains some of the best music I've ever had the pleasure to play to. Really, though, I thought Hunters was a fun little diversion, but I don't want them to make another one, simply because I've a feeling that the real Metroid games are going to be extremely scarce over the next few years and I want Nintendo's resources to go to making one of them and not another spinoff.