After completing 63 levels I would not recommend it. It's very chaotic and serves better as a learning experience for game developers. Main mechanics are explained in the help menu and provide you with the most basic information. Other things you have to figure out by yourself through many deaths. At first you won't even understand what's killing you. Some bullets can be avoided, some bullet-like bursts serve as powerups, some shapes can kill you even when bullying, but other can't - it's not clear at all why. Rules are just rules, you have to figure them out and try to follow them. Complexity curve is not consistent - some levels are hard and take 10-20 tries, while others are first try easy mode. Some level names seem meaningful while others are just for fun. Some angles and geometry introduce interesting behaviour which is never developed into consistent whole.
Never understood why people praise this game. Because it's funny? It gets old very fast. Because it's original? Yeah I've never seen anything quite like it, I've never played Tempest or any other tube-shooter. Is this a good introduction to the genre? No.