This is my guide for the Turbo Tortoise Achievement Version 0.24.4: Fission Update.
You are aiming for level 35 as seen in the image below.
Please Note Start with Engineer
1. Try and save your re-rolls only using them when you have dud upgrades.
2. Pick up Ataraxia asap.
Reason: the magnet range is important so you don't get caught out on the edges of the screen.in addition you can save up mods so your constructs can do more damage.
3. Complete all the mods in the Ally tree as soon as possible.
Note: don't waste re-rolls hunting for ally mods but when they do show pick them up.
4. Try and pick up the base entry constructs if you can just to actually have them.
5. Ignore the two mods in this tree. i have omitted them for convenience.
6. Just start these trees the way you see here.
7.Pick up Tempest Break.
8. Head towards the fusillade mod.
9. Pick up Tactical support and overseer last.
10. And finally at level 35 switch over to architect body mod this is why you want to hold onto all the re-rolls you can.