Airplane shooting game with weird easter egg

[MetroidPeter]

This was a 2D airplane dog-fighting game where you took control of a biplane and shot opponents out of the sky. This game was on PC (Windows XP). I don't remember if there was a single player mode, but I do remember the 2 player mode I played with my brother, where we both took control of a biplane and tried to shoot each other. The environment was 2 islands (I think) where the planes started, and they were just surrounded by ocean. Whenever one plane shot the other out of the sky, it'd make that classic sound of the biplane spiraling and coming down to the ground, before crashing into the water. One very weird thing I remember is that for some reason you could also play as Santa Claus, and I think it changed the bullets to candy canes or presents(?). Also, when shot down as Santa, instead of the biplane falling sound, he'd go "HO HO HO!!" over and over again, but as he fell, he was saying it faster and with a higher pitch, meaning he'd eventually sound like a chipmunk falling down. My brother and I thought it was hilarious.