Both are great games (so is the third part). The first levels in T1 are better than in T2 but the more you play the games T2 wins *slightly* the match. I don't like the colour palette in T2 on some levels, it's too "candy" for me. Level design in T2 has more imagination and variation. Soundtrack is perfect on both games but T2 has better sound quality and longer songs. T2 has also better sound effects and special effects, more weapons etc. It's bit like comparing Terminator (T1) compared to Terminator 2 (T2). T2 has more stylish special effects but the brutal story in T1 has its own strong moments. I would give Turrican 1 four stars and Turrican 2 four and a half stars out of five.
Terminator 1 I would give five stars out of five and Terminator 2 four stars out of five.