Somehow while creating the first build of UETF, I whiffed on delivering the 'fun' feeling.
When my room-mate tested the game, he said 'You have a long way to go until this is fun'.
Initially, I was shocked; UETF has always been about fun, how did I miss on that? I started with something that was fun and somehow had removed fun from the equation. How did it happen? In retrospect, I tried to make the game a little too clever - sometimes it's less fun to fight a few tough enemies than swarms of easy enemies. And although the AI directors were very unique compared to each other, the gameplay from wave-to-wave was very similar for each director.
I decided to completely re-do the model; I became convinced that something was wrong in the way I was spawning enemies. I went back to one of my sources of inspiration - the Helm's Deep battle in LOTR. What I noticed: The scene used tons of low level cannon fodder enemies with a few 'boss' type enemies added for challenge; the heroes killed strings of low-level enemies very quickly but had to put a lot more effort into killing 'boss' enemies. It allows the heroes to look like heroes and provides the feel of constant action without making the enemies total pushovers.
Based on this, I adjusted the game play. I created a set of 'cannon fodder' enemies with low hit points, and made sure the game spawned lots of them. Then I added different 'boss' enemies and had the game randomly add them into the mix. Bosses have more hitpoints and appear visually larger than the regular enemies. To balance enemy difficulty, I created a pool of 'spawn points' that the computer must draw from to spawn enemies. Boss enemies cost more than simple enemies. After that I created multiple enemy 'sets' for each AI to use, based on the current wave - later waves have access to bigger bosses and have a higher chance of spawning a boss.
The resulting gameplay is a step in the right direction; it adds a lot more action without diluting the 'tactical' aspect too much. It's a fun 15-30 second cycle. Your character feels like a hero but still has to try hard against enemy bosses. It's the kind of feel I want to have in a shooter and that I think that you will enjoy too.
Iterative Games: When the smart money is in gold, we're stocking up on lead