If you’re unfamiliar with Defense Grid, its biggest hook in the tower defense world is one that can be explained fairly easily. As you play, certain stages have levels with open grids on them for tower placement. The creeps, those are the aliens trying to steal your cores and take them back, will alter their paths based on your tower placement.
So, there’s a strategy in placing towers in specific spots rather than just plopping each gun down and upgrading to win. Now, I don’t think Defense Grid was the first to do this, but I do think it does it exceptionally well. Each level that has these open layouts is much more interesting and challenging than others, and command centers on the levels will let you annex new regions in order to push out the length of the creeps’ path.
You’re not only playing with your budget in order to come up with the best defense power, but you’re trying to lay out towers and boost blocks (basically, a tower upgrade spot that brings better stats to your big guns later in each level) so that you can do the most damage on creeps during their runs.
What’s frustrating about this game is that it’s impossible to have a planning phase. The levels start without you saying so, so you won’t be able to look at the map and decide which path is best before you start laying towers. Especially in the later game, the creeps move too fast and are far too strong for you to sit around and plan tower placement. I found this tough to contend with, especially since I’m the type of player who can’t play through tower defense games without getting perfect scores.
I like the dynamic paths and forcing creep behavior, I just wish the game would give me an option to pause and look at the map before it steals all my cores and causes me to lose. That’s probably just the perfectionist in me, though.