1. This Was A Friendly
Below is a chalkboard showing where fouls were called. In total, there were only 14 in the entire game. Only 9 in the first 85 minutes. The average number of fouls called per game ranges between 19 and 32. Both teams were giving each other plenty of space and there was a noticeable lack of physicality, especially on the part of the Americans as they committed only 4 fouls in the entire game. That's half the average for a team in MLS and a quarter of the average Bundesliga team's total.
2. The Game Defined in 30 Seconds
4:50 into the game saw a very nice sequence by the US. A Clint Dempsey cross found Jozy Altidore with the ball at his feet right in front of goal. As he has in every game under Jurgen Klinsmann, though, the opportunity was flubbed and promptly tackled away by the Belgian defender. Dembele cleared up the field and 30 seconds later Kevin Mirallas ('Kevin' is a Belgian name?) had coolly converted a Tim Howard spill with a beautiful chip. Yes, the US ended up equalizing later in the half, but that sequence set the tone for the entire evening. An early goal would have put pressure on Belgium, but instead it was the visitors who enjoyed the dream start.
3. The US CM's, sans Bradley, Lacking in Attack
Below is a chart of all the actions of Jermaine Jones and Sacha Kljestan. In total, the chalkboard gives them credit for 221 total actions between the two players. Only 6 of the 221 (~3%) occurred in the final quarter of the field. This is where the US badly misses Michael Bradley's ability to play box-to-box.
Oh, and also a bonus 4th point: Belgium is really really good.