Hunt down Santa by aiming with your mouse; click the left mouse button to shoot - for a more precise shot, hit the spacebar, and you'll have a scope. Hit the R key to reload when you're running low on ammo; make sure you reload often. Try not to make too many shots - the main point of the game is to keep your accuracy as high as possible. So if you're shooting, make sure you're hitting something.
Your main target and enemy - although you wouldn't expect it - is Santa, in this sniper game. He'll pop up where you least expect, and he can run quite fast sometimes. So don't give him any breaks - and if you're going for a highscore, try to shoot him in the head (in the middle) as much as possible. If you're using the pistol, you won't get a very accurate shot, so try and use the rifle - by pressing spacebar - as much as possible.
You're given sixty seconds per each level, with three levels total. In fact, the levels in Santa-Strike were actually inspired by the popular FPS computer game Counter-Strike. Actually, they're pretty much exact copies of levels from Counter-Strike, but that's not important. What's important is hunting down Santa - and you'll get quite good at it after playing a few rounds.
Overall, Santa-Strike is a relatively simple sniper game that doesn't offer much more than any other sniping game you've ever played. But that doesn't mean it's not fun - after all, we're talking about hunting Santa - and with the rifle, its pretty fun to pop off some headshots. Santa-Strike is great if you only play for a few rounds - but don't expect anything more from this short game. It's short fun, a lot of shooting, and you get to hunt down Kris Kringle - there's not much more you could want.