Blast is an exciting arcade game that offers you unlimited hours of space shooting adventures. Your objective is to destroy the enemy spacecrafts while making sure you don't collide with other ships or get hit by one of their missiles.
The game features nice, colorful graphics, lets you choose between 3 difficulty levels (Beginner, Intermediate or Advanced), and allows you to adjust music and sound effects volumes according to your needs. Another advantage is that you have access to gameplay instructions every time you launch the app on your Mac.
You can play the game by using the arrow keys for spacecraft movements and the Space bar for shooting the enemies. A nice feature is the Auto Fire option; this attribute eliminates the need to hit the Space key. The game doesn't feature a sequence of challenges. Instead, it lets you play until your spacecraft gets destroyed.
Blast will also keep track of your highest scores and display the top 100 worldwide scores.
All in all, I think Blast is a nice solution for spending your spare time in front of your Mac. It doesn't feature complex rules and controls and comes with a reasonable price.
Blast 1.7.6 is still available for older OSX versions.