Does it not open at all, or is it just that Idle Master doesn't start it? If it's not starting at all, you'll want to ask on the Undertale forums. If Idle Master isn't running it, does your Badges page say you have drops remaining? The yellow boxes in this image indicate where to check.
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=503188239

Games only give half the set (rounded up) through playing. Duplicates will count against your allotment of free cards. Trading/Selling/Using your cards will not grant yo additional/replacement cards.

You need to own the game in order to have drops. Idle Master won't run the game if you don't have drops.

The game(s) do not need to be installed since Idle Master doesn't start the game. It creates a window that claims to be the game and the Steam client doesn't bother to double check.

引用自 d1ştinctive°：

To have ''Idle each game individually'' or ''Idle games with more than 2 hours individually, then simultaneously'' ? Thanks in advance :)

Do you mean "LESS than 2 hours"?

Depends on the account. If you get drops with less than 2 hours of playtime, then "each game individually" is optimal. If your account requires 2 hours of playtime before drops start, idling all games up to 2 hours simultaneously and then each game individually is better.

If one of the computers is running a game (or pretending to in IM's case), attempting to open a game on the other system will cause Steam to give an error message and prevent you from opening the game. As long as you don't try to run a game on both systems at the same time, Valve doesn't care if your account is tied to multiple computers

引用自 ^7(^1)^2~=>WarLord<=~：

I have 4 cookies there _utma , _utmz , SteamMachineAuth, TimezoneOffset..... Which one do I pull info from?

There should be some labeled "steamLogin" and "sessionid". Try logging out and then back in, click the Remember Me box when logging in.

Find Settings.txt in whatever folder you installed Idle Master and open it, you'll see something along the lines of
If it doesn't exist in the Idle Master folder, create the file as a text document and copy/paste that section into it.

Now open up your browser of choice that you've recently logged into Steam on and open up your cookies (google will tell you how). Copy the SeassionID and SteamLogin for psteamcommunity.yuanyoumao.com . SessionID is a long string of alphanumerics, SteamLogin is an even longer string and has some symbols.

I you're comfortable with the command line, or batch files, it can be done. The FAQ touches upon it on the question about padding game time.

It says "4 out of 9 cards remaining"? I'd like to see a screen shot since it should say "4 card drops remaining" (assuming you have 4 drops remaining).

Looking at your Terraria badge I'd assume you meant that you have 4 out of the 9 cards, which is not what I asked. That just means you have 4 cards in your inventory, which has no bearing on how many drops you have remaining.

Does your Badges page actually say you have drops remaining for those games? The yellow boxes in this image show where you look
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=503188239

Even at 8.4 hours you should have enough playtime to have received your allotment of free cards, let alone 26 hours and 196 hours

引用自 Gordon FUCKING Ramsay：

stays i have no cards remaining but on tf2 i bought earbus 3 keys

It needs to be purchased from TF2's Mann Co. Store to qualify for card drops. Earbuds can not be purchased from the in-game store so they don't count.
Did you make the key purchases from the Mann Co Store, or from the Market? If purchased from the Mann Co Store, how much did each key cost? You need to spend 9$US for each card drop.

im not f2p on it

Assuming you gained a Premium account through purchases rather than the Upgrade gift, that just means you spent some money through the store, not necessarily $9US.

You can keep track of how much you've spent through the Mann Co Store by visiting your TF2 badge and clicking on the "How Do I Earn Card Drops?" link. It will pop up a new window show your progress towards your next drop.

引用自 Just Friis：

I have the same problem too. And i cant see which game it is idling.

If it's idling, then you do not have the same problem since the Idle Complete message it's not idling. If you're getting the Idle Complete message, same questions.