Space Giraffe is a game I've spent six years both loving and hating the hell out of.
On one hand, its iterative take on Tempest 2000/3000 is super engaging and satisfying. While it may invoke those older games on the surface, the bulling and Power Zone mechanics really make Space Giraffe feel like more of it's own game than the rehash it's often accused of being. The shooting and dodging are tight and satisfying and the risk vs reward elements make for some crazy intense shooty action. When all that comes together with the visuals and audio in the way that it's supposed to, Space Giraffe is simply astoudning to play and you can almost feel like you're in a trance when you're on a roll.
When it doesn't work however, the game just feels plain unfair and frustrating. Far too often, the emphasis on eye-searing visuals over gameplay can and will cause many unnecessary deaths due to how obscured the playfield can get. A large chunk of stages also to alter the game's rules subtly without telling the player, which just seems like a cheap and sloppy way to prohibit progress.
There will inevitably be frustration with this game, but I highly suggest at least trying the demo. It's something I've stuck with since its release and if you can manage to get over its initial quirks and don't mind some frustration later, Space Giraffe feels about as satisfying as Portal can be once you finally "get it."