There are only three enemy types and the sounds effects are a jumble of bleeps and bloops, but here's first-person shooter classic Wolfenstein 3Drunning on a Game Boy Color.

It's loaded onto a custom cartridge that features all 10 levels from the original game's first episode. The Game Boy Color in the above video is original Nintendo hardware, dating back to 1998.

This Game Boy port is the work of Swedish homebrewer Anders Granlund, who got started on the project back in October. He's been documenting the process of building the custom cartridge and convincing it to play a game that was never meant for Nintendo's handheld right here.

The port isn't yet completed -- the latest video is marked as the fifth work-in-progress example -- though it may soon be halted by hardware limitations.

The video's YouTube description notes that the cartridge is "currently using 123Kb out of the 128Kb ROM space." Granlund admits that he's "starting to reach the limit on what will fit."

Though with all 10 levels from the game's first episode out of the way, there's not a whole lot left. Granlund is still working on some of the extra bits -- including menus, elevators at the end of each level and game over/victory screens. He's also still tweaking AI behaviors.

The bulk of the work appears to be finished, however, as you can see in the video above. There's even custom-made box and cartridge art, though Granlund makes no mention of any plan to sell his work, and he would probably have trouble doing so since the WolfensteinIP belongs to Bethesda Softworks.