Today I got the framework setup for "Boss" battles - though they may be more like challenge battles. At the end of every 5th Wave the game now goes into a separate battle mode. This means the enemy spawners disappear, and battle music and a red vignette cover the screen. I created the first Challenge by 1 rail gunner on each wall and giving them a health that has to be knocked down. Previously all enemies just died upon impact with a bullet so this was a minor change to the enemy base classes, but for the better I think.
The change made me consider other gameplay elements. Like - should power-ups be earned during boss battles? What happens when the player dies in a boss battle - do they keep their existing power-ups? I had to think thru questions like these and determine how they impacted the balance of the game.
Speaking of balance - I think that is probably the hardest aspect of writing this game. It is way too easy to make a minor tweak in the game that makes it way too hard or way too easy. I very much underestimated how challenging it is to create good balance in a game.
Two Steps Forward, One Step Back
After all is said and done, I have a framework for boss battles. But in the process I introduced one bug that is hard to pin down. Sometimes the spawners don't turn off when I begin the boss battle and there is just no way to survive in that situation. I'm sure I'm just tired this evening and when I look at it with fresh eyes in the morning I'll see the problem. Also my High Score bug is back again :( It seems like such a simple thing but yet it's keeps popping up. I'll look at that tomorrow as well.