XR-4R3N4 by CrystalDaEevee, based on the track XR591
License: CC-BY-SA 4.0

Textures used that belong to the base game:
acid_lake.jpg
basicwall.png
columngreen.png
columnred.png
glassWindows.png
goal.png
light.png
metal_ground.jpg
metal_ground.png
red_dirt.jpg
road_dirt_red.jpg
sandred.jpg
stkflag_mandaravaMotors_a.png
stktex_tvVan_a.png

Textures that author made or modified from base game:
acid_glow.png
arrows(blue / neutral / red).png
ball.png
ball_gloss.png
barrier_grid.png
grid_glow.png
light_goal.png
metal_gloss.png
metal_transition_gloss.png
satellite.png
seating.png
stk_blueFutureSquareLight_a.png
stktex_tvVan_a_gloss.png

All new textures are under CC-BY-SA 4.0, all modified ones under CC-BY-SA 3.0 or 4.0 according to the texture's original license

.spm:
barrier.spm
field_lining.spm
soccer_ball.spm
xr_4r3n4_track.spm