Well, since I have too much spare time on Fidgit's hands (badum tish) I'll give Smogon a quick guide for Fidgit in arcade mode.
Revenankh
Rev is a big pain in the ass at first, simply because of its damn throw which can wipe you out easily, along with an annoying Shadow Punch. Use the heavy punch to force it away, as it has longer range than Rev's grab. Jump behind Rev when it uses Shadow Punch and use your heavy aerial to punish it. Earth Power can be used to juggle it and allow you to get a heavy aerial in.
Pyroak
Gah. Pyroak can be a pain, but your greatest weapon is your duck. Fidgit can duck right under all of Pyroak's projectiles, and a heavy crouching attack can force it back. Jump towards Pyroak, but from far enough away so Flamethrower misses, then hit it with a heavy aerial quickly. Comet Punch while it's still recovering, and back off to avoid Wood Hammer.
Stratagem
Stratagem is less dangerous, but still a pain. Use Earth Power to knock it around, then Comet Punch when it gets close. Your heavy duck attack can clear some space, and Rapid Spin should force it back and cause some nasty damage.
Syclant
Syclant can really put the hurt on. Using your heavy aerial will help immensely, and stick to your heavy punch to stop it throwing you around. Back up to avoid Ice Shard, or jump over and nail it with your aerials. Blizzard hurts bad, so try and not let it get you easily.
Arghonaut
Arghonaut is a surprisingly easy opponent (sometimes). Middle range Earth Power will knock it off its feet from the start if you back up, and your heavy aerial, as always, will serve as a very effective counterattack to Mach Punch assuming you space correctly. comet Punch can force it back out into Earth Power's range, and when it uses its series of punches, jump over and Rapid Spin it.
Note that this is all personal experience, so more experienced players will probably find over 9000 faults in it.
ungulateman