Spy Alley is a favourite game in my board game group - even though we have only had a few sessions. It is quick, funny and not complicated to learn.
There are a few issues in the rules so we have developed house conventions.
1 When in the Embassy Alley a spy landing on Spy Eliminator can only have a guess at one spy's identity. The last time we played we had 5 of the 6 players on Spy Alley and the eliminator killed 2 of the others and (without realising it) identified one others identity for the remaining 2 players and had one other player marked clearly one of two identities - it was an awful game as he was unstoppable from an early stage in the game.
2 The wild card free gifts are game winners - unfairly so. In fact as soon as one player has one the game seems to be over. So we specify the wild card must be a Key and taken immediately. Actually in some games we took them out.
3. If there are 2 or 3 players they get $40 each at the start of the game not $20 and $30. With so little cash buying keys is too hard and with so few players confiscating what you need is hard as well.
Oh and not a rule but we found 4 or 5 players much more fun that 2 or 6. Having one identity out of the game made it far more interesting.
1) This is why the alley is dangerous -- don't go in there is others are around.
2) Yes, Wild Cards rock. But just because someone gets one doesn't mean the game is over. It just means they become Public Enemy #1. There are plenty of ways to shift the balance of power. Typically in our games the Wild Card changes hands several times before all is said and done.
3) Yes, getting keys is hard -- that's why the game works.