Okay, now that sounds cool. Such a project sounds incredibly daunting, but I think it could be done by a kick-butt programmer.
One thing you have to remember is that it would need to be a gigantic app. There are hundreds of different enemies that each do different things, such as the walls of spikes, the bats that come up, the laser cannon, and the Delicious Fruit. You will probably have to have subroutines stored on the other pages.
Events are somewhat difficult to program. To write events, you would run a loop (either at the beginning of the game or in an interrupt) and check for all of the different events you can think of (key presses, proximity indicators, etc.). Then, store the results of those events in different memory locations, and then check those locations later in the game. However, I think that IWBTG could be done without events.