CrossOver works for a small number of games, such as Team Fortress 2 (based on half life 2 engine), and Counterstrike which uses the Half life 1 engine.
What's so difficult about using bootcamp the following way? To get the facts straight, it's Windows that takes the most amount of time, not bootcamp.
1. In OS X, restart, hold option key, wait 10 seconds (more or less) for OS X to restart and select windows partition.
2. Do something while windows boot up and becomes usable (5 minutes?), such as pay your bills, drink some water, lift some weights...
3. Play game
4. To restart back to Mac OS, just click the "Start" menu (yeah click start to shut down, typical of microsoft), and "Log off computer" and Restart, do something else while windows shuts down, which can be minutes.