I love the art style and the game is easy to get into. I only played for about 10 minutes and there didn't seem to be much strategy in the game other than chasing the enemy and making sure I didn't get hit whilst shooting them. Perhaps there is more strategy later on? There are plenty of people who like simple shoot-em ups so it's probably OK that there isn't much depth to the game but most of the great Shoot-em ups have strategic and tactical elements in them. Having said that it was simple, fun to play, ran fine on my machine and looks great.
Thanks, charliedog! There is some basic strategy, unique to certain ships or levels. For example, certain enemies have a particular weakness or a particular attack approach that works well with them - especially when you get to the various bosses and the huge capital ships later in the game. But you're right, for the most part it is a simple shooter. It was designed that way on purpose, since the primary audience for all of our games is children. Instead, we added depth to the game through the story and variety of mission styles.
The Linux version is now available! It can be downloaded from here: http://www.mygamecompany.com/Products/RickRocket/linux_download.htm