Dino Breakers was one of the first Unity projects that I created from beginning to end entirely on my own.  It was also one of my first experiences programming basic enemy AI which ended up being my biggest challenge.  I wanted the enemy dinos to patrol between two points and at certain times during the game, throw out random bad power-ups that would negatively affect the player.  This would offer some incentive for players to target the dinos first and they are also worth more points than the blocks.  However, the patrolling patterns proved to be more of a challenge than I originally expected with dinos running off into weird areas and not behaving properly.  In the end, I was able to fix the patrolling behavior once I simplified it and I had to cut out the behavior for throwing bad power-ups.