Slick2D is a great tool if you want to create games. It uses Java, which I am very familiar with, it's fast, it has tons of built in functionality which I could use and is easy to set up. One of the only downsides is the documentation. The website seems to have been moved recently, but the old one is still available. Then all of the sudden the new one went down for a while, which was irritating. I had little to no problems with the library itself though. Great stuff!
Happiness with Slick2D: 4/5.
I tried to make my code general-purpose, so I could reuse it for future projects. Since this project was relatively simple, it complicated the progress. However, should I ever write another game using Slick2D, I do have a lot of code I can reuse.
The code was rather messy due to the reusability I wanted to implement. Another factor that complicated the code is the moddability: almost everything is loaded from file. This causes some methods to be full of Exception handling. However, the code is efficient and runs fine, and it's still very readable.
Happiness with my code: 3.5/5.
I used pixelart created in GIMP for the game. I first went for an orthographic point of view, but due to time restrictions (damn February and its 28 days) I changed it to a top down game. The art is very stylized, but I think it looks pretty. Combined with a simple day-night cycle, I think I created a decent looking game. I'm pretty happy with the game icon too.
Happiness with the art: 3/5.
While Invasion doesn't sport much content out of the box, it's very open to be modded. When I was younger, I used to create levels all the time for the games I owned. It makes me sad that modding support seems to have disappeared almost completely from the AAA games industry, so adding it to my game was something I was very glad to be able to do.
I think AudioCube was a better game in the end, but I'm still glad with Invasion.
Happiness with the result: 2.5/5.
Average happiness: 3.25/5.