Scenario: Suppose I have on the battlefield Life and Limb, Sporemound, and Embodiment of Insight (for timestamp purposes assume they entered the battlefield in the same order I listed them). I play a Forest and proceed to put my triggers on the stack such that Sporemound's trigger resolves last and Embodiment's trigger resolves first, targeting the Forest I just played. When the Saproling enters the battlefield, due to Life and Limb it causes both creatures to trigger again and I choose the same order for triggers, making the Saproling a 3/3 Elemental with haste that is still a land before making another token. After gaining some arbitrary number of tokens and turning them into 3/3 Elementals, I destroy my Life and Limb to end the otherwise infinite loop.

Question: Are the tokens that entered the battlefield before I destroyed the Life and Limb 3/3 Saproling Elemental land creatures with haste and vigilance but with no land types, or are they just 3/3 Saproling Elemental creatures with haste?

It's a bit odd, but the "it's still a land" text doesn't actually mean that the permanent becomes a land. It just means it doesn't lose its previous types and subtypes. So, since no effect is turning the saproling tokens into lands, they aren't lands, and they don't have vigilance. This rule applies:

205.1b Some effects change an object's card type, supertype, or subtype but specify that the object retains a prior card type, supertype, or subtype. In such cases, all the object's prior card types, supertypes, and subtypes are retained. This rule applies to effects that use the phrase "in addition to its types" or that state that something is "still a [type, supertype, or subtype]." Some effects state that an object becomes an "artifact creature"; these effects also allow the object to retain all of its prior card types and subtypes.

As far as I can tell, they are still lands. Because of the rule Nylon cited, Embodiment of Insight's ability doesn't overwrite any types or subtypes, so the tokens never stop being Saprolings. This means there's no dependency. You apply Life and Limb's effect to make it a Forest Saproling land creature, then you apply Embodiment of Insight's ability to make it an Elemental in addition to those types. You end up with a 3/3 Forest Saproling Elemental land creature with vigilance and haste.

Note that Life and Limb is no longer on the battlefield So each saproling token is being affected by only one continuous effect: the one from Embodiment of Insight's triggered ability which, as I explained, doesn't turn the saprolings into lands.

It's the use of "retained" that made me wonder what the outcome was. I wasn't sure if the rule was interpreted such that a fresh timestamp was created that basically applied the land card type to the tokens (although if that were the case I suppose it would also apply the Forest subtype). The issue I have is that I see a difference between "retains its other types" and "doesn't lose its other types."

Oh, right. Forgot that important detail.

@Edacade: The word "prior" here is referring to the state one step earlier in the "layers" process of applying continuous effects. It does not refer to a state that existed at a previous time. At each moment, you apply continuous effects independently of any state at an earlier time. Since there's no continuous effect currently turning the tokens into lands, there's no land type for them to retain.

I forgot to give thanks for clarifying. I was 80% sure to begin with that it was the second option I gave that was the correct handling of the scenario, but I wanted to make sure that 20% wouldn't be a surprise issue. And checking the Comp Rules didn't help me (in fact, because of the "retained" it pushed me down to 70% sure that the second option was correct).