The ICBM gambit... (Tennison) Is it worth it?

Yes, it is.
Here is a link to a game I played where the oppenent resigned after move 6:

That was me. I shared the same game. I usually use this gambit as white against the Scandinavian, and it never went this far because black always did something else. I sort of realized too late I had fallen into the trap I always wanted to set up for someone else. I saw no point in continuing, so I think it is well worth it myself.

ok in a bullet game I suppose...

@billcourtney said in #2:

That was me. I shared the same game. I usually use this gambit as white against the Scandinavian, and it never went this far because black always did something else. I sort of realized too late I had fallen into the trap I always wanted to set up for someone else. I saw no point in continuing, so I think it is well worth it myself.

It's always fun until someone plays a different move

I know! Like, what if black reponds on move 3 with bishop f5? Welp, as long as the opponent falls for it, it is pretty successful.

@Thatonefrog said in #5:

I know! Like, what if black reponds on move 3 with bishop f5? Welp, as long as the opponent falls for it, it is pretty successful.
Well, even in a slower game where they may catch it with analysis, this stills leads to an interesting line of play for a longer game.

@ayoendy said in #4:

It's always fun until someone plays a different move

It's play one way or the other. It was nice. I never go into a fast game assuming I will win. I tend to lose on time almost all the time. This is a valuable chess lesson.