Riders on the space solver, the one and only

from PIL import Image
import struct
# no idea to what these offsets correspond
magic = b"\x07\x00\x85\x80\x04\x8A\x80\x08\xCF\xE0\x0B\xD4\xE0\x1B\x99\xC1\x1F\xDE\xA1\x23"

with open('data.bundle', 'wb') as bundle:
    bundle.write(magic)
    # images 1..6, with alpha
    for i in range(1, 7):
        img = Image.open(f"{i}.png")
        w, h = img.size
        bundle.write(struct.pack("<H", w))
        bundle.write(struct.pack("<H", h))
        bundle.write(b"\x04")
        # "fixes" coordinates, was too lazy to reverse the cycles
        img = img.transpose(Image.FLIP_TOP_BOTTOM)
        for r, g, b, a in img.getdata():
            # ALPHA PREMULTIPLYING!!
            r = (r * a) // 255
            g = (g * a) // 255
            b = (b * a) // 255
            # R G B A !!
            bundle.write(struct.pack("B", b))
            bundle.write(struct.pack("B", g))
            bundle.write(struct.pack("B", r))
            bundle.write(struct.pack("B", a))
        img.close()
    # background with no alpha, otherwise the same
    img = Image.open("7.png").convert("RGB")
    w, h = img.size
    bundle.write(struct.pack("<H", w))
    bundle.write(struct.pack("<H", h))
    bundle.write(b"\x03")
    img = img.transpose(Image.FLIP_TOP_BOTTOM)
    for r, g, b in img.getdata():
        bundle.write(struct.pack("B", b))
        bundle.write(struct.pack("B", g))
        bundle.write(struct.pack("B", r))