I honestly have no problem against Ice Climbers. I play against Grimice (local Ice Climbers, and apparently one of the better ones out there). I nearly always beat him unless I really play bad. But yeah, all I do against them is literally camp away, do nothing, until I see an opening where I am GUARANTEED to hit him without being punished (key word GUARANTEED, because likely is a trap which will result in getting grabbed). This usually comes up when he, say, desynchs his characters, but the timing of his desynchs results in a short period of time where both his popo and nana are free to be hit by an attack. Otherwise, I never approach him, never go anywhere near him, and avoid the possibility of getting grabbed at all costs.
Once they are separated, ALWAYS GO FOR NANA (well... unless you can down-tilt gimp popo for the stock or something, but otherwise, always go for Nana). Popo sucks at saving Nana against GaW, so we can just rack up the damage on her, and eventually get the kill. Don't worry if Popo hits you a few times, if you can kill Nana, then that 20% you received was well worth it, since now all he can do is... well, nothing. If he somehow does manage to get Nana back, Nana has way more damage, meaning the next time you hit them, Nana goes flying away, and they're separated again.
Also, a cruel trick you can do that works really well (if you really don't feel safe playing against both Nana and Popo) is if you have killed Nana, and you have the lead, don't kill Popo. Popo can't do much to you, and instead, you can just increase his damage with *insert move here*, while he may hit you a few times a minute at the most (unless you mess up horribly). But in the end, if he doesn't suicide, he runs the risk of having the timer run out on him. Grimice says that some Ice Climbers just suicide Popo once he's alone because of this fact.
But yeah, my favourite move by far in this matchup is Bair. There is literally almost nothing they can do against it. Popo can't powershield it, or Nana gets hit by it, and if they get hit by it, they can't punish you properly, or may even be separated (depends on your follow-up).
As far as stages go, obviously Rainbow Cruise, Brinstar etc. But otherwise, I always go for a platform stage, since platform camping is the easiest way to ensure you don't get grabbed. Grimice says Battlefield is his best stage (and claims it to be IC's best stage), so we always end up going there, but even if it is IC's best stage, it is an even better GaW stage, especially in this match-up.
As far as moves go, I almost always use Bair on him. I never use bacon (if predicted, can easily be grabbed), I never approach with Fair (can be grabbed easily), and... well, only use Bair when approaching/punishing. It works amazing.
But yeah, here's what I do:
1. Camp on the sides waiting for a mistake or opening.
2. Bair punish > Follow up if possible, safe, and guaranteed not to get grabbed
3. If IC are not separated, and a safe follow up is possible (usually Nair), continue following up until it is no longer safe to do so.
- If IC are not separated, and a continuing safe follow up is not available, go to 1.
- If IC are separated, go to 4.
4. Go all-out for Nana. Don't worry about attacking Popo much, as long as you don't stop the pressure on Nana. Nairs, up-airs, Fairs, and up-B are my most commonly used attacks here. Avoid Popo if possible, but really, don't worry if you get hit a few times. The trouble you're giving Nana is well worth it.
- If Nana survives, and is reunited with Popo, go to 1.
- If Nana dies, go to 5.
5. Play safe. Avoid getting hit at all costs. Yes, it's just Popo, but he can still rack up decent damage if you're not careful. Just wait for him to make a mistake and leave an opening, and punish when necessary. If you are winning (stock or percent), decide if you are going to try and time him out with just his popo. If you are doing so, play safe for the rest of the match. Otherwise, go for the kill when it is safe to do so.
I would say this matchup is 60-40 at the worst. I would probably say it's 65-35.
As long as you play this match-up smart, and don't make any mistakes (it's easier than it sounds), then you should have no problem against IC's. And spam Bairs.
Edit: wow, long post, and hi guys, it's been a while