If it was inclined exactly 90 degrees to the plane, the 'season' would depend on the amount of surface heating which now depends only on your latitude. Seasons would appear as different bands in LATITUDE with winter occurring at latitudes above...say 70 degrees, spring between say 30 - 70 degrees, and summer at 0 - 30 degrees...very approximately.
If the poles were in the plane of the solar system, every 3 months a different hemisphere facing the sun woould be in sunlight, with summer-like temperatures at the 'sub-solar latitudes' and as you approached the terminator region, you would have twilight. The dark hemisphere would stay dark for weeks or months and feel like arctic winter. It is all very complicated and I do not have much time to sort it all out, particularly the diurnal vs annual changes.
All answers are provided by Dr. Sten Odenwald (Raytheon STX)
NASA IMAGE/POETRY Education and Public Outreach program.